Sierra Sleep by Ashley
Sierra Sleep 12 Inch Pocketed Hybrid Full Mattress
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Verdict: if you want a supportive medium feel mattress that will not blow the budget, and you need it to work whether you sleep on your back, your side, or you cannot pick one, the Sierra Sleep 12 Inch Pocketed Hybrid Full earns its spot on our showroom floor.
How it is built
This is Ashley's 12 Inch Pocketed Hybrid, model M590, and the build follows a simple logic: put enough cushioning on top to take pressure off the shoulders and hips, then back it with a coil system that holds its shape for years instead of months. The top layer is a high density quilted foam for a soft, cushioned hand feel, followed by a flame retardant comfort fiber layer, standard in every mattress sold in the US. Underneath sits a gel memory foam layer positioned to support the lumbar region, the part of the spine carrying the most load while you lie down. A one inch layer of upholstery grade support foam transitions that softer top section into the pocketed coil core, where individually wrapped coils flex on their own instead of moving as one solid unit. Two rows of 13 gauge coils run the perimeter, so the edge of the mattress holds up when you sit on it to tie your shoes, not just the center.
Feel and support
Ashley builds this as a medium feel, and that tracks with how it actually sleeps. The quilted foam and gel memory foam layer absorb pressure at the shoulder and hip, while the coil core keeps the spine level instead of letting the midsection sink. Because the support comes from wrapped coils rather than a slab of foam, air moves through the mattress more freely than it would in an all foam design, which keeps the surface from holding heat overnight. At 12 inches thick, it has enough depth to feel substantial without towering over the frame, and it is compatible with adjustable bases if that is part of the setup.
Who it suits, who should skip it
- Back sleepers get steady lumbar support without the surface going flat under them.
- Side sleepers get enough give at the shoulder and hip to avoid new pressure points.
- Combination sleepers who shift positions overnight get a surface that responds evenly either way.
- Anyone set on a genuinely firm bed should keep walking the floor. This one is built to split the difference, not to feel like a board.
- Anyone chasing a deep, slow sinking memory foam hug should also test a plusher model, since the coil core here keeps you riding higher on the surface.
This mattress ships compressed in a box for easier delivery. Give it up to 48 hours after unboxing to fully expand before judging the feel, and plan on a compatible foundation or box spring, sold separately. It carries a 10 year non prorated warranty and comes in Twin, Full, Queen, and King, so the rest of the household can match sizes without changing the feel.
The only real way to know if a medium hybrid is your medium is to lie on one. Stop by one of our Kentucky showrooms and spend a few minutes on the Sierra Sleep 12 Inch Pocketed Hybrid in your own sleep position before you decide.
What makes this mattress different
Medium feel that splits the difference
Neither firm nor plush, this build is tuned to work across back, side, and combination sleepers instead of favoring one position.
Gel memory foam at the lumbar
A gel infused memory foam layer sits under the quilted top specifically to support the lower back, the area carrying the most weight while lying down.
Individually wrapped coils
The support core uses pocketed coils that flex independently under the body, instead of one connected coil unit moving as a block.
Reinforced perimeter for real edge support
Two rows of 13 gauge coils run the outer edge, so the mattress holds up when you sit on the side to get dressed, not just in the center.
Cooler than an all foam design
Air moves through the open coil structure beneath the foam layers, which keeps the surface from holding heat the way a solid slab of foam can.
12 inch profile
Substantial enough to feel like a real mattress on the frame, without the extra height that complicates fitted sheets or a low bed frame.
Adjustable base compatible
The hybrid build flexes cleanly with a powered base if the bedroom setup calls for one.
10 year non prorated warranty
Ashley backs the build for a full 10 years with no prorated coverage reduction over time.
A quilted, gel infused comfort system over a reinforced coil core
The Sierra Sleep 12 Inch Pocketed Hybrid, Ashley model M590, layers a cushioned top over a coil support system built to last. From the top down: a high density quilted foam layer for a soft hand feel, a flame retardant comfort fiber layer required in every mattress sold in the US, a gel memory foam layer positioned to support the lumbar region, and a 1 inch layer of upholstery grade support foam that transitions into the coil core.
That core is a pocketed coil system, individually wrapped coils that respond to the body independently rather than as one connected surface. Two rows of 13 gauge coils reinforce the perimeter, holding the edge of the mattress steady under weight instead of letting it collapse near the border. The open structure between coils also lets air move through the mattress, which keeps the surface from trapping heat the way an all foam build can.
The result lands at a medium feel: enough cushioning at the shoulder and hip to relieve pressure, with a coil base underneath that keeps the spine level instead of letting the midsection sink.
See the full Sierra Sleep lineup →Built for back, side, and combination sleepers
Back sleepers: the coil core keeps the hips from sinking while the gel memory foam layer supports the lumbar region, so the spine stays level.
Side sleepers: the quilted foam and gel memory foam layer cushion the shoulder and hip enough to relieve pressure without losing support underneath.
Combination sleepers: a medium feel with no strong lean toward soft or firm means the surface responds evenly no matter which position you land in overnight.
Couples: the reinforced perimeter coils keep the edge of the mattress usable, so neither sleeper feels like they are rolling toward the middle.
Hot sleepers: the open coil structure under the foam layers lets air move through the mattress, which helps it sleep cooler than a solid all foam design.
Probably not for you if: you want a genuinely firm, sleep on top of it feel (ask the floor about a firmer model in the lineup), or you want a deep, slow sinking memory foam hug, since the coils here keep you riding higher on the surface than an all foam bed would.
Specifications
| Height | 12 in |
|---|---|
| Feel | Medium |
| Firmness | 5 out of 10 (10 = firmest) |
| Construction | High density quilted foam top, flame retardant comfort fiber, gel memory foam lumbar layer, 1 inch upholstery grade support foam, and a pocketed coil core with reinforced 13 gauge perimeter coils: 12 inches total. |
| Cooling | Individually wrapped coils leave open airflow beneath the gel memory foam comfort layer, helping the mattress sleep cooler than an all foam design. |
| Warranty | 10 year non prorated warranty |
Frequently asked questions
How firm is the Sierra Sleep 12 Inch Pocketed Hybrid?
It is built to a medium feel, positioned between soft and firm. The quilted foam and gel memory foam top layers add cushioning at the shoulder and hip, while the pocketed coil core keeps the spine supported underneath. It is intended to work reasonably well across back, side, and combination sleeping positions rather than favor one.
What is the Sierra Sleep 12 Inch Pocketed Hybrid made of?
From the top down: a high density quilted foam layer, a flame retardant comfort fiber layer, a gel memory foam layer for lumbar support, a 1 inch layer of upholstery grade support foam, and a pocketed coil support core with two reinforced perimeter rows of 13 gauge coils.
Is this a foam mattress or a hybrid?
It is a hybrid. Gel memory foam and quilted foam comfort layers sit on top of individually wrapped pocketed coils, so you get pressure relief from the foam and consistent support and airflow from the coil core underneath.
Does the coil edge actually hold up, or does it collapse near the border?
Ashley reinforces the perimeter with two rows of 13 gauge coils specifically to resist that collapse, so sitting on the edge of the mattress to get dressed does not feel like the support drops off.
Will this mattress sleep hot?
It should sleep cooler than a solid all foam mattress. The open structure between the pocketed coils allows air to move through the build, which helps carry heat away from the gel memory foam layer above it.
Is it compatible with an adjustable base?
Yes, the hybrid construction is designed to flex with an adjustable base if that is part of your bedroom setup.
What sizes does this come in, and does the feel change by size?
The 12 Inch Pocketed Hybrid is available in Twin, Full, Queen, and King. The construction and feel are the same across sizes, so the household can mix sizes without anyone getting a different mattress experience.
How should I set this mattress up after delivery?
It ships compressed in a box. After unboxing, give it up to 48 hours to fully expand before judging the feel, and place it on a compatible foundation or box spring, which is sold separately.
Does this mattress come with an at-home trial?
No. Sierra Sleep mattresses at Mattress Overstock do not include an at-home trial. The way to know if the feel is right for you is to try it in person at one of our Kentucky showrooms before you buy, where you can lie on this exact model in your own sleep position.
Buy it from people you can actually visit
- Free local delivery To your home across Central & Eastern Kentucky.
- Free setup We place and set up your new bed in the room.
- Free old-mattress haul-away The old one goes out the same day the new one comes in.
Independently owned in Kentucky since 2012. Walk in any day (no appointment) and someone who actually knows the floor will help you find the right fit.
Still deciding?
Try it in person at any Kentucky showroom
Walk into any Mattress Overstock location, lie down, and feel the difference yourself. No appointment, no pressure. Our team has over 100 years of combined mattress experience and we're here to help you find the right fit.
