Sleep Number I-8 Mattress Review – Best Model For You?

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The I-8 mattress from Sleep Number has a little bit of everything: a plush mattress top with cooling technology, body contouring foam, and Sleep IQ technology built-in. Is it the right Sleep Number mattress for you? Read on for my full review.

Construction Overview

The I-8 is one of three mattresses in Sleep Number’s Innovation Series line of beds. The series also includes the I-10, and I-LE mattresses as well.

The I-8 mattress has a 13” profile, which is measured from the base to the highest loft of the mattress.

The mattress will come with either one or two air chambers (depending on what size bed someone gets). The air chambers will inflate and deflate according to the Sleep Number setting. This will determine the level of support/firmness the mattress provides.

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


Directly below the air chamber(s) is a 1” base pad and above the air chamber is 3” of PlushFit foam that is specifically designed for Sleep Number to help relieve pressure.

The foam is made to relieve pressure in seven specific areas: head, shoulders, lower back, hips, knees, lower legs, and feet.

The I-8 mattress is made with a polyester/polypropylene blend fabric that is designed to be soft and breathable.

The top of the I-8 mattress is a duvet pillow top that includes 2” of Hypersoft Quilting Foam for a plush surface and Outlast temperature balancing technology to minimize temperature swings.

It’s worth noting that the Sleep Number Sleep IQ Technology, which will track someone’s sleep and help them find their optimal Sleep Number setting, is included in the price of the I-8 mattress.

Optional: People can add a FlexFit Adjustable Base for their bed that will allow them to raise the head and foot of the bed.

To sum it up, here are the layers of the I-8 mattress starting from the base:

  • Base
  • 1” foam base pad
  • Air chamber(s)
  • 3” PlushFit comfort foam (with seven zones designed to contour to the body)
  • 2” of Hypersoft Quilting Foam
  • Duvet pillow top with Outlast temperature control technology on the surface
  • Polyester/polypropylene blend fabric overall

Firmness Level

When it comes to firmness, there are several factors in a Sleep Number bed that will affect how firm the bed is.

  • The Sleep Number: The air chamber/air chambers in your mattress will inflate/deflate according to your Sleep Number. The higher the Sleep Number, the more air in the air chambers and the firmer your mattress will be.
  • The Comfort Layer: There are several types and thicknesses of foam comfort layers in Sleep Number beds. Denser and thicker comfort layers will provide more support and increase the firmness of your mattress.
  • The Mattress Top: Sleep Number offers a variety of mattress tops. Plusher pillow top style mattress tops will be less firm than a flatter mattress top.

In particular, the I-8 mattress has 2” of quilting foam sewn into the woven duvet mattress top along with a 3” layer of PlushFit comfort foam above the air chamber. This makes it a softer (less firm) mattress.

A Customer Service tea member told me that it is firmer than the bestselling P-5 mattress (according to a Sleep Number team member).

Who Might Want To Consider This Mattress:

  • People Who Sleep Hot. There is temperature-regulating technology built into the mattress top of the I-8 mattress. Outlast Technology (the same kind found in Slumber Cloud’s Dry Line Protector mattress protector) is designed to pull heat away from your body and re-distribute it during the night so you sleep comfortably.
  • People Who Need Pressure Relief. The 3” foam comfort layer in the I8 mattress is designed to contour specifically to seven areas of your body to relieve pressure: head, shoulders, lower back, hips, knees, lower legs, and feet.

Who Might Not Want To Consider This Mattress:

  • People Who Are On A Budget. The I-8 retails at $3,499.99 for a Queen size mattress. This does include Sleep IQ Technology, but not a FlexFit adjustable base or other features. Sleep Number does sell one Queen mattress for less than $1,000 (the C-2) and several for under $3000, including the popular P-5 mattress.

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 their desire. A lot of couples found the I-8 was a really comfortable option that left both partners happy.


I read a lot of reviews from people suffering from back pain or back-related injuries who found relief with the I-8 mattress. Many of them wrote reviews to talk specifically about how much the mattress – and in many cases, the addition of an adjustable base – helped them sleep better.


Most Common Complaints

The #1 complaint across the board with this mattress is that it does not feel the same as the showroom model. So many people felt that they received something different than they ordered. Many said it felt harder and less plush than what they felt in the Sleep Number store.

SleepNumberI8ReviewShowroom2 SleepNumberI8ReviewShowroom

Customers who purchased this mattress several years ago reported having to replace many parts – including foam layers and the Sleep Number remote – and/or having to pay someone to come out and make repairs on their bed.


Overall, people just felt that they overpaid for the quality and value of the I8 mattress (and/or adjustable base).


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

The I-8 mattress has a lot going on – it has a specific combination of features that could be the perfect fit for someone.

A person might pick the I-8 over another Sleep Number mattress if they struggle to stay cool at night, have back, hip and other pain from their current mattress, want the ability to adjust their firmness any given night, and have $3,499 to spend on a Queen mattress.


The I-8 mattress could be a great option for couples (or individuals) who are looking for flexible comfort and a way to stay cool through the night.

The biggest features of this mattress include the Outlast Technology that regulates body temperature and the 3” PlushFit comfort foam layer exclusively designed to relieve pressure.

Check out our full Sleep Number review

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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.