SweetNight Prime Review

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

Note: This mattress is flippable as well as offering different firmnesses on the head and foot. Our tests, data, and scores are based on the medium side of the mattress.

At NapLab, we put each mattress to the test.

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

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

Factor	SweetNight Prime	Average
Overall Score	7.76	8.63
Price (Queen)	$949	$1,102 (Memory Foam only)
Cooling – Score	8.0	8.7
Sinkage – Depth	2.07″	2.15″
Sinkage – Feel	Moderate	Moderate
Motion Transfer – Score	6.9	8.2
Motion Transfer – Acceleration	11.82 m/s²	8.66 m/s²
Response Time – Score	6.3	8.9
Response Time – Mostly Recovered	0.7 sec.	0.4 sec.
Response Time – Fully Recovered	2.2 sec.	0.9 sec.
Bounce – Height	5.93″	9.72″
Bounce – Feel	Very Low	Moderate
Edge Support – Score	9.5	8.6
Edge Support – Sitting	2.75″	4.05″
Edge Support – Lying	Excellent	Good
Sex – Score	7.3	8.5
Pressure Relief – Score	8.0	8.8
Comfort Layer Thickness	4.0″	4.1″
Mattress Thickness	12″	12.0″
Off-Gassing – Score	8.3	8.4
Off-Gassing – Smell	Strong	Strong
Off-Gassing – Days	6 days	6 days
Company – Score	8.0	8.7
Trial	100 nights	169 nights
Warranty	10 years	25% have lifetime warranties, average of other 75% of mattresses is 13 years

How is the SweetNight Prime Different?

The SweetNight Prime is $949 for a queen and is 4% more expensive than average for a foam mattress (avg. is $913).

Cooling on the SweetNight Prime is good, but not exactly great. During our tests, I felt a slight to moderate level of heat retention around my body.

The Prime uses an all foam, traditional memory foam design, which isn’t doing the mattress any favors with respect to breathability.

• 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

The thin cover is a plus, but it’s pretty basic, lacking any type of cooling fibers, phase change materials, or other cooling additions.

In our objective tests, we measured a max temperature of 83.8°F. From minutes 0 to 1 the temperature dropped by 5.5° and by 9.7° from minutes 0 to 5.

Heat Dissipation Over Time

If you describe yourself as a “warm” or “hot” sleeper then I would advise caution with the SweetNight Prime. Ultimately, there is only so much an all-foam memory foam mattress is able to do for cooling.

The SweetNight Prime has a moderate level of sinkage. In our pressure point sinkage tests, we measured a sinkage depth of 2.07”. This is 0.15” less sinkage than the average of 2.22” (based on all of our tests to date).

The level of sinkage is documented in the image below.

The Prime has a very traditional memory foam feel. It’s extremely slow to respond to changes in movement. When you first lie on the mattress it’s quite hard, taking several seconds before your body fully sinks into the foam.

Once you do sink down there is a dramatic and exacting contouring hug around the body. This is a very traditional memory foam feel. If you like the feel of more old-school memory foam then you’ll love this feel. If not, then the Prime probably isn’t right for you.

The SweetNight Prime has a high level of motion transfer. In our tests, we measured 11.82 m/s² of acceleration range. This is 4.13 m/s² more motion transfer than the average of 7.69 m/s².

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

I was quite surprised by the high level of motion. Typically, traditional memory foam mattresses are able to absorb and disperse energy better. I suspect the reason we’re seeing higher motion here is due to the harder feel when you first lie down.

It’s got such a slow response time and such a hard initial feel that it rebounds much of the initial motion spike.

Our motion transfer chart, which visualizes our accelerometer data, shows the highest spikes from 0 to 0.14 seconds. After 0.14 seconds motion drops off dramatically and by 0.50 seconds we have returned to near-zero levels.

While the initial energy spike is higher than expected, the motion duration is quite level. There is a slight level of motion from 0.14 to 0.50 seconds, but even there, it is quite low.

Certainly, the silver lining of motion transfer is that it doesn’t last very long. The fastest mattresses are able to return to near-zero levels within 0.3 seconds. The SweetNight Prime isn’t quite to that level, but it’s not far off either.

Response time on the SweetNight Prime is a bit of a mixed bag. In our response time tests, we measured a mostly recovered response time of 0.7 seconds. This is 0.24 seconds slower than the average of 0.46 seconds. However, the full recovery time is considerably slower at 2.2 seconds.

The level of responsiveness is documented in the video below.

This is 1.3 seconds slower than the average fully recovered response time. The slower response time gives the mattress a more traditional memory foam feel. For many sleepers, it will also make the mattress more difficult to move around on.

The mostly recovered speed of 0.7 seconds is the measurement we use to determine response scoring. As a result, the score is still pretty good.

However, more sensitive sleepers should carefully consider whether the slower full recovery speed of 2.2 seconds will be problematic. This slower speed is considerably different than more traditional coil mattresses (which are effectively instant recovery).

The SweetNight Prime has a low level of bounce. In our tests we measured a total bounce height of 5.93”. This is 3.72” less bounce than the average of 9.65”.

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

The low bounce of the Prime makes it harder to move around on and inhibits sex performance. In general, I like to see 8-12” of total bounce height.

It’s a sweet spot that maximizes the benefits while minimizing the negatives. At 5.93” the Prime mattress is considerably lower than that 8-12” threshold.

Edge support on the SweetNight Prime is a mixed bag as well. Sitting edge support is outstanding. However, lying edge support leaves something to be desired.

In our sitting edge support tests, we measured 2.75” of sitting sinkage compression. This is 1.61” less sitting sinkage than the average of 4.36”. The mattress does a fantastic job of creating robust support even when sitting directly on the edge of the mattress.

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

All that said, lying edge support was good, but far from great. The traditional memory foam contour makes the edge support feel a bit squishy.

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

The heavier you are the more notable it will be. Most sleepers will likely prefer sleeping at least a few inches away from the edge in order to feel fully supported.

Our sex rating formula looks at 5 different factors weighted based on their importance.

All factors are not equal in terms of significance, but each plays an important role.

Three of the most important factors are listed below with the associated testing scores:

In addition to the factors above, there are two other we consider as well, including pressure relief and cooling.

Here’s a look at the breakdown of how these 3 factors rank within the full formula:

We use the scores from all factors, plugged into the formula above, to derive a sex score for each mattress.

Sex Factor	Factor Weight	Score	Rating
Bounce	65%	6.2	Low
Edge Support	20%	10	Outstanding
Noise	5%	10	Minimal
Pressure Relief	5%	8.0	Good
Cooling	5%	8.0	Good

This mattress has pretty low bounce, which is not especially conducive to good sex performance and hurts the score a bit. This mattress just soaks up so much of the energy.

For sleeping, this kind of energy absorption is usually good, but for sex, it’s quite problematic. Despite its other positive features and performance, many may simply find it uncomfortable for the dance without pants.

Pressure relief on the SweetNight Prime is good, but not great. As we’ve discussed, the mattress has a very traditional memory foam feel.

It’s quite hard when you first lie down and/or change position and gradually softens as it conforms to your body. However, even when it fully softens the pressure relief doesn’t blow me away.

During our tests, I felt a slight level of building pressure points in my shoulders. In my view, this is just the way the more traditional memory foam is.

For those who love this specific feel, the pressure relief dynamic can be great. However, I do fear that many sleepers (especially those who have slept on more traditional mattresses for most of their lives) will find the pressure relief dynamic to be too foreign.

Off-gassing on the SweetNight Prime mattress is fairly strong right out of the box. It took 6 full days for the mattress to completely off-gas.

That being said, once the mattress off-gasses, this isn’t really a factor that has any long-term effects on the mattress itself.

To speed up off-gassing, consider leaving all fitted sheets or other bedding off of the mattress for the first few days. Turn on a fan, open a window, or use an air purifier to help encourage the flow of clean air around the mattress.

SweetNight has pretty standard terms and conditions. They offer a 100-night trial period and a 10-year warranty. Shipping and returns are both free if the mattress ends up not working out.

Company Factor	Factor Weight	Score	Data
Trial Period	15%	8.0	100 nights
Warranty	10%	8.0	10 years
Shipping	5%	10	$0
Returns	20%	10	$0
Trust	50%	7.0	Fair
Country of Origin	0%		South Korea

Firmness on the SweetNight Prime mattress is quite unusual as the head and foot have different firmnesses, in addition to the mattress being flippable (with a different firmness on each side).

Considering all areas of the SweetNight Prime, the overall firmness ranges from 5.5-8 out of 10.

The difference in firmness between a head / foot of the mattress is more minimal, whereas the difference in firmness between the top and the bottom is more dramatic.

The medium side ranges between a 5.5 and a 6 out of 10, where 10 is the most firm.

The firm side ranges between a 7.5 and a 8 out of 10, where 10 is the most firm.

Overall, this feels like an unusual approach to firmness, but for some it could work. It’s designed so that side sleepers can get better pressure relief and sinkage, while at the same time providing the increased support and firmness that back sleepers often need.

The SweetNight Prime has excellent support. In our tests, I felt fully supported in all sleeping positions. While the pressure relief leaves something to be desired, the support dynamic is great.

The mattress uses 12” of total thickness with 4” of comfort material and a 2” transitional support foam layer, give or take. The foam has a curved design so the exact thickness varies depending on what position of the mattress you are on.

Still, overall it’s got all the basic design building blocks that I look for. My only concern is for the overarching feel of the mattress itself. The more traditional memory foam feel could cause some sleepers to feel more entrapped or overly enveloped by the contouring, slower-responding foams.

Yes, it’s fully supportive, but it has the classic memory foam feel. This feel is neither good nor bad.

It’s just a more unique feel that can be more polarizing with respect to sleeper preferences. Some sleepers love, and others really don’t.

Considering the flippable design and different firmnesses at the head / foot, there is a firmness to suit nearly every type of sleeper’s needs.

Medium Side

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

As you can see in the table below, a firmer feel is often more appropriate for heavier sleepers. especially those who sleep on their back or stomach.

Firm Side

Sleeper Weight	Stomach Sleepers	Side Sleepers	Back Sleepers
Under 150 lbs.	Maybe	No	Maybe
150-250 lbs.	Maybe	No	Maybe
250-300 lbs.	Yes	Maybe	Yes

Design

The SweetNight Prime mattress is an all-foam mattress with a 10″ or 12″ mattress height and offers flippable firmness.

This mattress uses curved layers of foam to provide a slightly different firmness and feel at the head / foot of the mattress.

Materials

There are four layers of foam that make up the Prime mattress. From top to bottom, these layers are listed below:

• 4” memory foam
• 2” poly foam
• 4” support foam
• 2” poly foam

The Cover

The cover of the SweetNight Prime has a dark gray and light gray checkerboard pattern. It is designed to prevent pilling and has an anti-slip finish to help keep the cover in place.

It is thin and breathable for a modern feel across the surface of the mattress. This thinner cover also allows sleepers to engage more deeply with the memory foam top layer, instead of adding a plush quilted cover for extra thickness.

The Comfort Layer

The comfort layer of the Prime mattress depends on what side of the mattress you’re on.

For the medium side, the comfort layer is made up of memory foam with a 4.0″ perforated slab right at the top of the mattress.

But on the firm side, the comfort layer is only 2.0″ thick and is made of poly foam.

Both of these materials will feel dramatically different, with the memory foam offering more hug, contour, and a slower response. The poly foam has a bit more pushback and a firmer feel.

The Support Layer

Regardless of which side of the mattress you’re on, the support layer is the same.

Support is made up of a 2.0″ poly foam and 4.0″ high-density support foam, for a total of 6.0″ of support material.

Product Evolution

The SweetNight Prime mattress was launched in spring of 2023. Since its launch, there have been no changes to the mattress.

The launch of the Prime mattress comes after the earlier launches of two other mattresses in the collection—SweetNight Dreamy Hybrid and the SweetNight Twilight Hybrid.

SweetNight Prime vs. Dreamy

Considering a SweetNight foam or hybrid mattress? Check out the mini comparison below for the Prime vs. Dreamy mattress.

Comparing these two, the Prime mattress has lower levels of motion transfer, and better edge support. All other categories are pretty similar in terms of overall performance.

Other Mattresses to Consider

Not sure that the SweetNight Prime is the right pick for you? Check out these three other top-rated all-foam mattresses for alternate options.

Frequently Asked Questions

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