Amerisleep AS4 Mattress Reviews (2026)

The AS4 gives you a plush, body-hugging feel without turning into a total sink-in bed, and in our testing it stayed impressively calm when a partner moved. The trade-offs are the slower foam response, edges that compress more when you sit, and support that likely will not be firm enough for most stomach sleepers.

• Who It’s For

  • Side sleepers who want deep shoulder and hip relief

  • Couples who want a quieter, less bouncy surface

  • Back sleepers under about 200 pounds who like a softer feel

• Who It’s Not For

  • Dedicated stomach sleepers who need firmer hip support

  • People who want a springy, responsive hybrid feel

  • Anyone who relies on very strong edge support

We used our How We Test Mattresses process on the AS4, then repeated partner-movement routines with Marcus and with Jenna and Ethan as a movement pair. We scored Support, Cooling, Pressure Relief, Motion Isolation, Responsiveness, Edge Support, and Durability on a 5-point scale using nightly notes plus repeatable drills, including sink-depth checks, seated edge tests, partner-turn tests, and timed repositioning. Our scores reflect the mattress after break-in, not just first-night impressions.

In our testing, the first thing that stood out was the soft landing at the shoulders and hips. On my side, pressure eased quickly, and on my back the bed still felt organized through the middle instead of collapsing. Marcus (6'1", about 230 lbs) said it was comfortable but close to too soft once he rolled toward his stomach, and he also noticed warmth building by early morning. Jenna and Ethan focused on couple sleep: when Ethan turned over, Jenna felt more of a muted ripple than a full-body shake. During our sit tests, the edge compressed more than a typical hybrid, but it never felt unstable.

• What we liked

  • Strong pressure relief without obvious loss of support

  • Motion stayed localized and the surface felt calm

  • Comfortable for reading or laptop time without sharp pressure build-up

• Who it is best for

  • Side sleepers who want cushion without a hammock-like dip

  • Couples who are sensitive to movement

  • Back sleepers who prefer medium-soft comfort

• Where it falls short

  • Too soft for many stomach sleepers and heavier back sleepers

  • Slower to reposition on than bouncier foams or hybrids

  • Edge support is fine for sleep, but less ideal for frequent sitting

• Mattress type: all-foam memory foam

• Firmness: medium-soft (brand rates it 4/10)

• Profile height: 12 inches

• Cooling tech: Refresh Cooling technology

• Comfort layer: 4" Bio-Pur® foam

• Transition layer: 1" Affinity layer with HIVE®

• Support core: 7" Bio-Core® foam

• Sizes: see our Mattress Sizes Guide; AS4 is sold in Twin, Twin XL, Full, Queen, King, California King, and Split King

• Price example at the time of review: Queen $1,749, with a listed promo price of $1,249

• Sleep trial: 100 nights

• Warranty: 20 years

• Shipping/returns: free shipping and free returns

Pick the AS4 if you want a medium-soft feel, sleep on your side often, and care more about quiet, low-motion sleep than bounce. If you are heavier, sleep mostly on your stomach, or sit on the edge a lot, the softer top and average edge support are meaningful trade-offs. Hot sleepers should view it as better than basic foam, not a true cooling specialist.

For alternatives, hot sleepers who still want a cushioned feel may prefer something more cooling-focused, like the Helix Midnight Luxe. Stomach sleepers who need firmer hip support will likely do better on a firmer foam or hybrid, such as the Amerisleep AS2.

This mattress has a soft, contouring comfort profile, so it can let the hips sink too far for dedicated stomach sleepers and many heavier back sleepers. The foam feel also means slower response when you change positions quickly, and the perimeter compresses more than coil-reinforced designs. If you want a lifted, springier surface, this likely is not the right fit.

• Why choose the AS4

  • Plush pressure relief without excessive sink

  • Excellent motion isolation for couples

  • Medium-soft comfort that stays more level than many ultra-plush foams

• Alternatives to consider

  • Saatva Classic: stronger edge support and a bouncier surface

  • Helix Midnight Luxe: better airflow and easier repositioning

  • Tempur-Adapt: a more classic contouring option for foam fans

• Give the mattress a full 24 to 48 hours to settle before you judge the feel.

• Use a breathable protector; thick waterproof covers can dull the cooling surface.

• Pair it with a solid, non-flexing foundation to keep the support consistent.

• If you sleep hot, start with percale sheets and a lighter comforter before blaming the mattress.

• Rotate the mattress every 3 to 6 months to help even out early wear.

• Side sleepers may do best with a slightly higher-loft pillow to keep the neck neutral.

• Back sleepers can try a small knee pillow if they notice lower-back tightness.

• Couples should avoid overly bouncy bed frames that can amplify movement.

• If you sit on the edge every day, avoid lingering in the same spot to reduce premature softening.

For most stomach sleepers, yes. In our testing, the hips tended to dip, and that can pull the lower back out of neutral alignment.

Less than many classic memory-foam beds, but it is still clearly a foam feel. Quick turns take more effort than they do on a hybrid.

It was one of the calmer all-foam feels we tested. Partner movement stayed muted, and the surface stayed quiet through the night.

Usually yes for sleeping. For frequent edge sitting, expect more compression than you would get from a coil-reinforced hybrid.