FORM Prime X Review

In This Review
Performance Tests | Firmness | Support & Sleeping Positions | Design | Materials | Comparisons | FAQs

At NapLab, we put each mattress to the test.

We test 10 different factors that impact the performance, comfort, and feel of the mattress. We then take the results of those tests and compare them to every mattress we’ve tested to date.

Check out the full performance table below to see how this mattress ranks:

Factor	FORM Prime X	Average
Overall Score	9.19	8.52
Price (Queen)	$2,999	$2,253 (Specialty only)
Cooling – Score	9.0	8.6
Sinkage – Depth	2.92″	2.25″
Sinkage – Feel	Extremely Deep	Moderate
Motion Transfer – Score	8.7	8.2
Motion Transfer – Acceleration	7.98 m/s²	8.77 m/s²
Response Time – Score	9.9	8.8
Response Time – Mostly Recovered	0.2 sec.	0.4 sec.
Response Time – Fully Recovered	0.4 sec.	1.0 sec.
Bounce – Height	9.56″	8.65″
Bounce – Feel	Moderate	Moderate
Edge Support – Score	8.4	8.7
Edge Support – Sitting	4.75″	3.85″
Edge Support – Lying	Excellent	Good
Sex – Score	8.5	8.2
Pressure Relief – Score	10	8.6
Comfort Layer Thickness	7.50″	4.34″
Mattress Thickness	16.00″	12.30″
Off-Gassing – Score	8.1	7.9
Off-Gassing – Smell	Strong	Strong
Off-Gassing – Days	7 days	8 days
Company – Score	10	8.8
Trial	365 nights	193 nights
Warranty	Lifetime	40% have lifetime warranties, average of other 60% of mattresses is 13 years

How is FORM Prime X Different?

The FORM Prime X is a 16.00″ specialty mattress with an overall performance level that is higher than average and a price that is also higher than average as well. The result is a luxury-tier mattress at a price you’d expect for the higher performance.

Advantages

Specific advantages of the Prime X include better cooling performance, lower levels of motion transfer, faster material response time, better sex performance, and exceptional pressure relief.

The Prime X has a 7.5″ comfort layer and a 16.0″ overall thickness.

Off-gassing is faster than average as well, with all odors dissipating by day 7 (compared to the 8-day average).

Neutral Factors

This mattress has extremely deep sinkage and moderate levels of bounce. Both sinkage and bounce are preferential factors, but for sleepers who like sleeping “in the mattress”, the Prime X can have the right feel.

Disadvantages

The price will be a disadvantage for some sleepers, with the Prime X costing nearly 2X the price of the average mattress we’ve tested.

In addition to the higher price, the Prime X also has deeper sinkage and weaker edge support, which may be an issue for some sleepers.

The FORM Prime X has excellent cooling. During our tests, I did not feel any significant level of heat retention around my body. Overall, the mattress maintained a comfortable temperature.

When we consider the material design, it’s easy to see why. First up, we have a comfort layer stack that’s a mix of latex, gel pad, poly foam, and memory foam, with the memory foam layer being only 1.0” thick and further away from the surface.

• Baseline Temperature – the temperature of the mattress before anyone lies on it
• Maximum Temperature (0 minute) – the temperature of the mattress after lying on it for 15 minutes
• Ending Temperature (5 minute) – the temperature of the mattress after being lied upon and having no one on it for 5 minutes

In my view, the latex and gel are doing the heavy lifting for cooling. Latex naturally resists heat and is perforated, while the gel layer uses a grid design, creating tons of small air pockets to increase airflow and resist heat buildup.

While we do have poly foam within the pillow top, it’s less dense and more breathable, while the other poly foam and memory foam layers are further away from the surface of the mattress.

On the base of the mattress, we have an 8.0” pocketed coil unit, which brings additional airflow into the mattress.

In our objective temperature tests, we measured a max surface level temperature of 91.0° F. This is 0.7° warmer than the average of 90.3° F, based on all of our tests to date.

After getting off the mattress, the temperature declined by 3.4 degrees from minutes 0 to 1, which is 1.4 degrees less cool than the average 0 to 1 minute decline of 4.8 degrees.

When we consider the combination of objective data, my subjective experiences, and an analysis of the materials, I’m confident in my view that cooling is excellent.

The FORM Prime X has extremely deep sinkage. During our tests, we measured a pressure point sinkage depth of 2.92″. This is 0.67″ more sinkage than the average sinkage depth of 2.25″, based on all of our tests to date.

The mattress creates a balanced, body-contouring hug. The overall feel is one of balance and that balance comes from the wide variety of materials used, including a euro style pillow top, Talalay latex, gel pad, poly foam, memory foam, and pocketed coil support.

With so many different materials, the mattress creates a more even feel. While it has latex, it doesn’t feel like a latex mattress.

The level of sinkage is documented in the image below.

While it has a gel grid, it doesn’t really feel like a gel mattress. The same is true for each of the individual layers. These layers create a more blended feel. In my view, the feel is on par with many other luxury-level hybrid mattresses we’ve tested in this price range.

Unlike the less expensive FORM Core and FORM Core Hybrid mattresses we previously tested, in which you can really feel the gel layer in a meaningful way. By contrast, the gel layer here is just one among many comfort layers.

As such, its feel isn’t as pronounced, and instead you feel the cumulative mix of different material types.

The FORM Prime X has a low level of motion transfer. During our tests, we measured a total acceleration range of 7.98 m/s². This is 9% less motion transfer than the average of 8.77 m/s².

The lower motion transfer was a bit of a surprise, as typically mattresses with more bounce and more resilient materials, like latex and gel, create higher motion. However, that’s not what we measured with our accelerometer.

Seemingly, the ultra-thick comfort layer at 7.50” is doing a good job of dispersing energy and preventing it from traveling significantly across the mattress.

In addition, the 3.0” quilted euro top cover is also likely to have an outsized impact on that energy absorption.

The level of motion transfer is also documented in the video below.

In our motion transfer chart, which visualizes our accelerometer data, we can see the highest motion peaks from 0 to 0.25 seconds. Motion drops off thereafter, but remains spiky through 1.0 seconds.

By 1.30 seconds, we’ve returned to near-zero levels of energy, which is 0.40 seconds longer than the average motion duration of 0.90 seconds. Given the type of materials that this mattress uses, the higher motion duration makes sense.

Talalay latex, gel, and coils especially simply create more energy.

While the layers of poly foam and memory foam around them are helping to contain and localize the energy to a smaller location, we can still see some of that energy transferring across the mattress.

Nevertheless, while motion duration is worse than average, motion intensity is better than average. Overall, I’m pleased with this level of motion transfer and expect most sleepers will find it satisfactory.

The FORM Prime X has an extremely fast mostly recovered response time and a very fast fully recovered response time.

In our mostly recovered test, we measured a recovery speed of 0.2 seconds, which is 0.22 seconds faster than the average of 0.42 seconds, based on all of our tests to date.

In our fully recovered responsiveness test, we measured a recovery speed of 0.4 seconds, which is 0.62 seconds faster than the average of 1.02 seconds.

The level of responsiveness is documented in the video below.

The mostly recovered response speed is tied for the fastest we’ve tested to date, while the fully recovered response time is just 0.1 seconds slower than the fastest we’ve tested.

These material recovery speeds make this mattress incredibly easy to move around on, easy to change positions, and easy to get in and out of bed.

The FORM Prime X has a moderate level of bounce. During our tests, we measured a total bounce height of 9.56″. This is 0.90″ more bounce than the average of 8.66″, based on all of our tests to date.

The higher bounce is a product of the Talalay latex, gel grid, and hybrid design. While the memory foam within the core is likely suppressing some level of bounce, the other materials that surround it are highly responsive and resilient.

The level of bounce is also documented in the video below.

Together, this design creates plenty of bounce, which is able to deliver better sex performance and better ease of movement.

The FORM Prime X has fair sitting edge support and excellent lying edge support.

In our sitting edge support test, we measured a sitting sinkage compression of 4.75″. This is 0.90″ more sitting sinkage than the average of 3.85″, based on all of our tests to date.

The level of edge support while seated is documented in the images below.

While lying directly on the edge of the mattress, I felt that the support was excellent in all sleeping positions. This mattress is equipped with a layer of support foam that wraps the entire perimeter of the mattress.

That foam is 3.5” wide and 8” tall and is certainly helping to improve edge support for the mattress. That said, based on the data, it seems clear that the edge foam is having a larger impact on lying edge support, while sitting edge support struggled more.

The level of edge support while lying is documented in the images below.

With a combination of an extra-thick comfort layer, squishy gel layer, and extremely deep general sinkage, this mattress material design sets the stage for less-than-incredible sitting edge support.

The FORM Prime X has good sex performance. On the positive side, noise is minimal, pressure relief is outstanding, and cooling is excellent.

In addition, bounce measured in at 9.56”, which is notably more than average. Extra bounce makes sex easier, less tiring, and more fun.

Where the mattress isn’t so great is edge support, which we measured at 4.75” of sitting edge sinkage. A squishier edge reduces the usable surface area of the mattress. While it’s not as important as bounce, it’s still a notable factor.

Sex Factor	Factor Weight	Score	Rating
Bounce	65%	8.5	High
Edge Support	20%	7.8	Fair
Noise	5%	10	Minimal
Pressure Relief	5%	10	Outstanding
Cooling	5%	9.0	Excellent

When we look at the combined picture, we see sex performance earning a score that’s good and better than average, but it’s also fair to say that amorous activity performance isn’t incredible.

The FORM Prime X has an outstanding level of pressure relief. During our tests, I felt no significant pressure points on my body.

The mattress is equipped with 7.5″ of comfort material, which is 3.16″ more comfort material than the average comfort layer thickness of 4.34″, based on all of our tests to date.

This mattress comfort layer is incredibly thick. In fact, it is ranked #4 (tied with 3 others) as the thickest comfort layer we’ve tested to date (out of 451 other tests). All of that extra material is able to deliver fantastic comfort and pressure relief.

The overall feel is one of balance, and that balance comes from the variety of different materials used, including a euro-style pillow top, Talalay latex, gel grid pad, poly foam, memory foam, and pocketed coil support.

With so many different materials, the mattress creates a more even feel. While it has latex, it doesn’t feel like a latex mattress. While it has a gel grid, it doesn’t really feel like a gel mattress.

The same is true for each of the individual layers. These layers create a more blended feel.

In my view, the overall feel is similar to many other luxury-level hybrid mattresses I’ve tested within this price range. In our objective pressure mapping tests, we measured a max PSI of 0.48, which is well within the 1.0 max PSI threshold that we ideally want to see.

Pressure Relief (PSI)	Average	Maximum
Side Sleepers	0.12	0.41

Pressure Relief (PSI)	Average	Maximum
Back Sleepers	0.07	0.48

Pressure Relief (PSI)	Average	Maximum
Stomach Sleepers	0.07	0.21

When I consider our objective pressure mapping tests, material thickness, material quality, and my subjective experience on the mattress, I’m confident most sleepers will find the pressure relief to be outstanding.

The FORM Prime X had a strong smell upon the initial arrival. The mattress smelled for 7 days. This is 0.7 days shorter than the average smell duration of 7.7 days.

FORM mattresses come with a 365-night trial period and a lifetime warranty. Shipping and returns are both free.

Company Factor	Factor Weight	Score	Data
Returns	40%	10	$0
Trial Period	30%	10	365 nights
Warranty	20%	10	Lifetime
Shipping	10%	10	$0
Country of Origin	0%		USA

Comparing 118+ brands tested to date, the average trial period is 193 nights, 172 nights less than FORM offers.

The FORM Prime X is also backed by a lifetime warranty, a perk offered by only 40% of mattresses that we test.

The FORM Prime X is only available in a single firmness option—medium-firm. This is a 6 out of 10 firmness rating, where 10 is the most firm.

Support on the FORM Prime X is excellent. During our tests, I felt well supported in all sleeping positions.

Support Factor	Data
Comfort Layer	7.50″
Support Layer	8.50″
Firmness	Medium-Firm
Body Contour	Balanced
Zoned Support	Yes
Reinforced Edge	Yes

The mattress is equipped with an 8.5″ support layer. This is 0.54″ thicker than the average support layer thickness of 7.96″, based on all of our tests to date.

Mattresses that create the best support meet two major requirements. First, they support the body, delivering a neutral spinal alignment. And second, they create ample comfort and pressure relief. FORM Prime X easily met both of these requirements.

This mattress has a medium-firm feel. That’s a 6 out of 10 on our firmness scale, where 10 is the most firm. This firmness works well for the vast majority of sleepers and all sleeping positions.

Check out the table below to see the sleeper weights and sleeping positions that would be best suited for this mattress.

Sleeper Weight	Stomach Sleeper	Side Sleeper	Back Sleeper
Under 150 lbs.	Yes	Yes	Yes
150-250 lbs.	Yes	Yes	Yes
250-300 lbs.	Yes	Yes	Yes

In all mattress tests at NapLab, we make it a point to cut the mattress open to assess the material quality. We use a densimeter to measure foam density levels and a digital caliper to measure coil thickness.

Denser foams are typically higher quality, perform better, and last longer, while thicker coil wires also typically provide better durability and support. Material quality on this mattress is a bit of a mixed bag.

On the higher quality side of things, we have the Talalay latex, gel pad, 3.81 PFC memory foam, and coil unit (which measured a 14.5 gauge). However, I’m less impressed with the density of the poly foams throughout the mattress, which we measured at a range of 1.27 PCF to 1.54 PCF.

These are definitely on the lower side. Overall, I’d still describe this as a quality mattress, though I would have liked to have seen higher-density poly foam used. Moving on, this mattress uses zoned support via the pocketed coil unit. According to the product page, there are 7 different support zones.

Zoned support creates targeted support with varying support based on what each part of the body needs. The coil unit has 600 individual coils on the Queen.

Based on all of my tests to date, an analysis of the materials, and my subjective experiences, I’m confident most sleepers will find support on the FORM Prime X to be excellent.

The FORM Prime X is a 16.00″ specialty mattress that comes in a single firmness option—Medium-Firm. Its design of a polymer grid, latex, memory foam, poly foam, and pocketed coils gives the mattress a more unique feel compared to more traditional hybrids.

Design Factor	Data
Type	Specialty
Thickness	16.00″
Cover Type	Pillow Top
Weight	159 lbs.
Has Handles	Yes
Fiberglass-Free	Yes
Ships in a Box	No

This mattress has a pillow top cover and ships compressed in a box. It is fiberglass-free and has handles on the sides of the mattress for easier transport or rotation of the mattress.

The FORM Prime X is 16.00″ thick and contains a combination of different material types. From top to bottom, here is a full list of the materials used in this mattress:

Layer Type	Thickness	Manufacturer’s Specs	Tested Specs
Pillow Top	3.00″	Not Available	1.40 PCF
Talalay Latex	1.00″	Not Available	3.83 PCF
Gel Pad	1.50″	Not Available	51.65 PCF
Poly Foam	1.00″	Not Available	1.54 PCF
Memory Foam	1.00″	Not Available	3.81 PCF
Support Foam	0.25″	Not Available	1.23 PCF
Pocketed Coils (Interior), Poly Foam (Edge)	8.00″	Not Available	14.5 Gauge, 1.65 PCF
Support Foam	0.25″	Not Available	1.27 PCF

The FORM Prime X has a 3.0″ pillow top cover that is designed for a plush, contouring feel and exceptional cooling.

The fabric itself is an marketed as having “cool on contact” material. When paired with the polymer grid beneath, the cooling of this mattress was, indeed, excellent.

The comfort layer is 7.50″ thick, including the 3.0″ pillow top cover. Beneath the pillow top is a myriad of different foam materials. Directly below the cover is a 1.0″ latex followed by a 1.5″ gel pad.

This gel pad is wrapped by a foam perimeter, which gives the mattress a more restrained feel along the edges.

Beneath the gel pad is a 1.0″ poly foam and, lastly, a 1.0″ memory foam layer (gray foam).

The support layer is 8.50″ thick and made of three layers of foam. The bulk of the support layer is an 8.0″ pocketed coil system sandwiched between a 0.25″ support foam on the top and bottom of the coils.

Product Evolution

FORM is a newer mattress brand, poised to develop a line of specialty mattresses that use a polymer grid for comfort and pressure relief. FORM is the sister brand of Amerisleep, which has a longer history, having been founded in 2010.

FORM launched their brand with four mattresses—the Core, Core Hybrid, Prime, and Prime X Hybrid (this review).

As this is a newly launched model there have been no changes to design since launching. If / when changes are made to the design we’ll add those to this section.

Other Mattresses to Consider

Frequently Asked Questions

Still have questions? Check out some of the top FAQs on the FORM Prime X mattress below and get the answers you’re looking for.