Sleep Number M-7 Review – Best Fit For You?

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The M-7 Sleep Number bed offers a unique blend of customizable firmness and soft cushion with its 4” layer of gel memory foam.  Are you ready to sink into this mattress? Read on for my full review.

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Construction Overview

The M-7 is the only mattress in the Memory Foam series of Sleep Number beds and has a 12” mattress profile.

Unlike the Classic Series or Performance Series beds, the M-7 features 2” of foam underneath the air chamber(s). The Customer Service rep told me this adds height and support to the feel of the bed.

As with all Sleep Number beds, the M-7 will come with either one or two air chambers (depending on what size you get). The air chambers are what inflate and deflate according to your Sleep Number setting. This will determine the level of support your mattress provides.

A bed with two air chambers is part of Sleep Number’s “DualAir™ adjustability” feature. It allows you to adjust firmness and support on each side of the bed to your Sleep Number setting. The hoses to pump air into the chamber are 4ft in length.


Above the air chamber in the M-7 is 4” of gel memory foam. Within this 4” of memory foam, there is a portion made with CoolFit technology that helps you sleep cool, as well as an additional layer of memory foam for a total of 4” of foam thickness.

The M-7 mattress is made with a rayon/polyester blend fabric that is designed to be soft and breathable.

The top of the mattress is specific to the M-7. This is how the Customer Service rep described it to me: M7 has a unique soft flat cover, no pillowtop. It is a grey color. This then allows the body to sink in slightly to the gel. But it still has the cooling and ability to change Sleep Number settings.

It’s worth noting that the Sleep Number Sleep IQ Technology, which will track your sleep and help you find your optimal Sleep Number setting, is included in the price of the M-7 mattress.

Optional: You can add a FlexFit Adjustable Base for your bed that will allow you to raise the head and foot of the bed.

Firmness Level

The air chamber(s) in a Sleep Number bed inflate and deflate as you adjust the firmness of your mattress. The higher your Sleep Number, the more air will fill the chamber and the firmer the bed will feel.

The least amount of firmness comes in the C-2 model, which offers no foam comfort layer at all. The only cushion is from fiberfill sewn into the top of the mattress.

Naturally, this will be the firmest Sleep Number bed because there is basically no cushion between the mattress and the air chamber.

The M-7 model features 4” of gel memory foam, which is less dense (has more cushion) than the foam found in Classic Series or even the Performance Series mattresses, like the bestselling P-5. Your body tends to sink into memory foam, allowing the foam to contour to your body.

The M-7 model does have 2” of foam underneath the air chamber(s) which the Customer Service representative told me adds sturdiness to the memory foam.

The 2” foam layer and 4” gel memory foam layers make the M-7 model less  firm than the models in the Classic Series or Performance Series of Sleep Number beds.

Related: Best Mattresses

You Might Want To Consider This Mattress If:

  • You Like Memory Foam. With 4” of gel memory foam in between you and the air chambers in the M-7 bed, you really need to enjoy sleeping on memory foam before you consider this mattress. One Customer Service representative told me that the M-7 is usually only recommended for people who sleep on memory foam and who are looking to make it adjustable (by adding one of Sleep Number’s FlexFit Adjustable Bases).
  • You Are A Hot Sleeper. The 4” of exclusive memory foam features CoolFit gel technology for a cool sleep surface. This layer resides above the air chambers so it will be felt underneath the mattress top. Be careful about adding additional mattress pads/toppers as they may lessen the benefits of this technology.

You Might Not Want To Consider This Mattress If:

  • You Like A Firm Bed. The 4” gel memory foam layer can be found below the mattress top but above the air chamber. This is going to allow you to sink deeper into the mattress, while still being able to adjust firmness with the air chambers. It will not be a naturally firm bed.
  • You’re Not Ready To Make An Investment. At $3,500 for a Queen-size mattress, the M-7 is a serious purchase. While that price does include Sleep IQ Technology, it does not include an adjustable base – which allows you to raise the foot/head of your bed as well as other nice features.

Most Common Pieces Of Praise

  • Couples and partners seem to love Sleep Number beds for their dual air chambers and ability to adjust the firmness to your desire. It appears to still be the case with the M-7 and couples who like memory foam like this mattress as well.

  • People who wanted a mattress with the intention to help relieve pressure in certain areas of the body – like back and hips – were satisfied with this mattress. They liked how the memory foam contoured to their body but they could still adjust the level of support.

Most Common Complaints

  • People felt that the 4” gel memory foam layer shifted/ slipped off the air chambers section frequently.

  • Another consistent complaint was that the M-7 was simply not comfortable enough for its expensive price tag. People who not only purchased the M-7 mattress but a FlexFit Adjustable Base and other components felt that the quality and value of their bed did not match the high price point.

Why Would Someone Pick This Model Over The Other Sleep Number Mattresses?

The main reason someone would pick the M-7 over other Sleep Number beds is the 4” cooling gel memory foam layer.

This memory foam layer is thick, will allow you to sink into the bed and its CoolFit technology will (hopefully) help keep you from sleeping hot.

As I mentioned earlier, a Customer Service team member told me this bed was really only recommended for people who enjoy sleeping on memory foam beds but want to add an adjustable base that will allow you to raise/lower the foot and head of your bed (among other features).


The M-7 bed is ideal for an individual – or couple – who love to sleep on memory foam and are looking to stay cool at night.

The mattress has a lot to offer those who know what they’re looking for (memory foam) and those who have money to spend – as the mattress is probably even more comfortable when used with one of Sleep Number’s FlexFit adjustable bases.

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Katie Golde

Katie manages the day to day operations of the Mattress Clarity news site and reviews sleep products in addition to writing and editing sleep news. She hails from Austin, where she lives with her growing family. She is a Certified Sleep Science Coach and has a master’s degree in Journalism from Northwestern University and has a background in health and science content. Her work can be found in print and online publications like Discover Magazine, USA Today and The Huffington Post.