Odds are, you've heard of Sleep Number before, regardless of whether you were shopping for a mattress or not. The company’s been around since 1987 as Select Comfort, but rebranded to Sleep Number in 2017. It has since gained momentum through strategic marketing and brick-and-mortar stores.

The company offers 11 models of smart beds with varying levels of AI integration that track your heart rate, respiratory rate, and sleep quality. You can control the mattress’s firmness level, and with the optional base, the angle of incline and decline. With sensors, the mattress also tracks your sleep progress through the Sleep Number app. This is meant not only for convenience but also to eliminate the need for remotes and even a sleep tracker—everything you need is in one place.

I decided to test the P6 mattress from Sleep Number’s Performance Series, as it was designed to provide the most pressure relief, and the FlexFit 3 adjustable base to control its incline, decline, and foot warming.

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All mattresses in the Performance Series, including the P6, have a “Responsive Air” auto-adjusting pressure-relief setting. This involves pressure sensors that automatically adjust the bed’s topmost zoned air chambers for customized pressure relief.

The P6 is 11 inches tall, thanks to an extra inch of ceramic gel foam compared to the other two smart mattresses in the Performance Series, the p5 and the pSE. This foam is designed for increased cooling and pressure relief. I wanted to see if that was truly the case, and if it would help support my ongoing back issues and promote deeper sleep. Plus, the idea of not having to wear a sleep tracker to bed was intriguing to me, even from a sensory standpoint.

Photograph: Julia Forbes

When I think of mattress giants with established histories, such as Serta, Sealy, and Tempur-Pedic, Sleep Number also ranks among them, thanks to its significant influence. Founded in 1987, the company now operates 610 brick-and-mortar mattress stores across the United States. Despite this, I have never completed as extensive testing over one of its mattresses in my nearly six years of testing mattresses—until now.

The usual claim to fame of high-tech smart beds, including the P6 air bed, is that each side can be modified. While Sleep Number isn’t the only innovative mattress brand out there that offers this, its name is a nod to the vast range of firmnesses available in its beds. Each sleeper can pinpoint the exact firmness they prefer, and wherever they land on a scale of 1 to 100 is ultimately their “Sleep Number setting.”

Stay Firm

Typically, mattress firmness is measured on a scale of 1 to 10, with 10 being the firmest. The P6’s 100 total firmness levels are a whole other ball game. To achieve this range, the P6 relies on dual air chambers that deflate to get a softer feel or inflate to become firmer. Hoses attach the air chambers on each side of the P6 mattress to a small, underbed engine that plugs into the wall. The P6 also needs to be synced with the Sleep Number app and your home’s Wi-Fi to implement these firmness changes. If there is a power disruption, that’s a problem, as your bed essentially deflates and goes offline—so maybe consider adding a power station to go with the bed if power outages are a concern.

It took two days of trial and error to land on my personal “Sleep Number,” as neither end of the firmness spectrum was very comfortable. The softest setting, 1, felt like a deflated air mattress with a slab of foam on top; 100 felt so firm it was painful for my pressure points. I spent most of my time within the 40 to 50 range, as it was the closest to medium-firm I could get on my side of the bed. On my husband’s side, he aimed for the upper 60s. Each side of the P6 (and Sleep Number beds in general) has its own internal air chamber, so couples can get precisely what they prefer—hence why smart beds are so popular for pairs.

Photograph: Julia Forbes

However, achieving the ideal firmness level is only half of the experiential equation to me. The pressure-relief features touted by this bed were why I chose the P6 model to begin with. This is where “Responsive Air” comes into play. While there are layers of foam used in the P6, including an extra inch of ceramic gel foam, it was actually the five chambered zones I felt more than anything else. Mini air chambers, or “comfort zones,” are responsible for fulfilling this feature. They rely on numerous sensors to detect even slight variances across the surface. If one area of your body is pressing in more than the rest, the P6 will use this feature to adjust support and contour around that particular area. As a side sleeper, my shoulders often take the brunt. With the setting enabled, I could feel in real time when the bed adjusted in different spots to offset pressure buildup. It’s a bit jarring at first (especially in the middle of the night, when you hear the bed’s engine running to accomplish this), but it did make a difference in distributing my weight. But if you find it to be disruptive, the Responsive Air feature can be toggled off in the app.

Keeping Track

The sensors aren’t just responsible for Responsive Air; they also track your biometric data, known as Sleep Number’s SleepIQ technology. SleepIQ is an AI algorithm that learns more about you the more you sleep on the bed, including sleep quality metrics like time to fall asleep, restlessness, and actual sleep time, and whether you leave the bed. It also tracks more advanced biometrics, including breathing rate, heart rate, and heart rate variability (HRV). Heart rate variability is a measure of the time between heartbeats. In a nutshell, it’s a way to check in on multiple bodily systems that your nervous system (both the sympathetic and parasympathetic systems) is in charge of overall.

All these data points combined make up your SleepIQ Number, a numerical score that reflects how well you slept. But I wanted to know how P6 was able to pull together all this in-depth data, supposedly on par with that of my fitness tracker. My fitness tracker, an Apple Watch SE, can measure heart rate, HRV, and sleep by directly contacting my skin. I figured that the sensors picking up this data within the P6 would be similar, perhaps right underneath the mattress cover. Turns out, they’re at the bottom of the bed.

Screenshots: Julia Forbes

I spoke with Raj Mills, Sleep Number’s senior vice President of partnerships and research. She tells me, “Our AI models take into account foam depth and still maintain the same level of accuracy regardless of how far below the surface of the bed the sensors are.” She shares that they are cohesively performing a ballistocardiograph, which monitors the blood flow generated by the heart and ultimately determines your heart rate score. How effectively they can do so is debatable.

Ultimately, I found there was quite a bit of variance in terms of the nightly score calculated on both ends. On good nights, both pointed to higher scores, but the final number could differ by up to 10 points. On the Sleep Number app, I found it concerning that most of the time, my Sleep Score numbers were not as high as I thought they would be—my average for the three-week test period was a 74.

Matrix Mattress

If you prefer a remote, that's either a separate cost ($50) or potentially a different bed altogether. The only way to operate this mattress is by creating an account and downloading the app in advance. Security of one’s personal data is top of mind for many, and I wanted to know how the vast quantities of data accumulated by Sleep Number’s customer base were managed. When you first sign up for your account, you can either share your data with Sleep Number or opt out altogether. For those who share their data willingly—about 550,000 individuals, according to Mills—Sleep Number's data science team performs research and presents findings from its consumer base at major sleep conferences, including SLEEP and World Sleep Congress.

It's a comprehensive data set to work with, and it continues to evolve through the adaptive AI at play, which includes SleepIQ technology. According to Mills, the company's AI models are structured to analyze sleepers at an individual level, because every sleeper has a different build, age, pain issues, and various needs. According to Sleep Number's privacy policy, the company doesn't sell your information to third parties, and you can withdraw your consent to share information at any time. At the end of the day, Sleep Number is a business that can potentially use your data to develop new products, and it's up to you whether that's worth it or not.

Power Couple

An adjustable base is what enables each side of the mattress to independently adjust head and foot angles. I tested the FlexFit 3 adjustable base alongside the P6 mattress, which is Sleep Number’s top-of-the-line offering. It offers timed foot warming (which takes about two minutes to heat up and has a two-hour default setting) to help blood flow away from your core and aid faster sleep. There is also a zero-gravity setting, partner snore (elevates the head and neck slightly to help open up airways), and motion-detect underbed lighting. I loved the gentle light source for late-night bathroom breaks, and the split king adjustability allowed me to partake in late-night reading without disturbing my partner. However, the only feature that separates the FlexFit 2 base from the FlexFit 3 is the inclusion of foot warming, and it’s a $400 upcharge for a queen size.

Photograph: Julia Forbes

However, I’d say the FlexFit 3 is a worthy investment, and one I’d personally spring for before getting the P6 mattress itself. It doesn’t have to be paired with a Sleep Number mattress, but the mattress has to be compatible with an adjustable base. The FlexFit 3’s head and foot adjustability helped mainly when I wasn’t sleeping (reading and relaxing), but I can’t imagine skipping out on foot warming or even the under-bed lighting. I felt like I fell asleep faster with the foot warmer, primarily because I can’t regulate my body temperature well. The timer feature shuts off when I’m asleep, so I don’t wake up overheated. But for hot sleepers who like cooling mattresses and have no interest in foot warming, you could probably skip this in favor of the FlexFit 1 base (no foot adjust, zero gravity, or foot warming) or the FlexFit 2.

Beta Mode

During my time testing the P6, I’ve gone back and forth on whether having 100 firmness levels at my disposal was too much of a good thing, or the very thing I’d been missing out on in my years of mattress testing. On the one hand, the firmness variance was convenient, allowing me to make it slightly softer when my pressure points needed it. Then, on the other hand, unless you have sleep issues stemming from illness or injury that would benefit from a feature like this, you technically aren't giving your body a consistent surface to get used to. Mattress brands usually require 30 nights before customers can initiate returns, so that they can get used to it. With all these firmnesses to pick from, it’ll likely take you longer to make up your mind.

Photograph: Julia Forbes

Over the years, testing mattresses, I’ve found that some mattresses labeled “adjustable base compatible” really aren’t. The inner pocketed coils nearly always pop and creak as the head and foot of the bed move up and down. This doesn’t bode well for long-term durability and support—not to mention, it’s like nails on a chalkboard to me. Ultimately, it’s another reason I’d point to keeping the bed and base bundled together, akin to Apple device enthusiasts sticking to what they know rather than venturing into Android territory.

My takeaway from this testing experience is that I would get the FlexFit 3 adjustable base in a heartbeat—the foot warming, automatic underbed lighting, and various incline and decline settings just can’t be beat. I’m appreciative of all the P6 offers, but think that its specialization is best for sleepers in very distinct scenarios. If you’re someone with severe pressure point pain (perhaps you got a hip replacement or spinal fusion), or deal with health or sleep disorders where tracking sleep quality is imperative, I’d quickly point you in the direction of the P6.