by The Amerisleep AS3 beats the Helix Midnight in motion isolation and pressure relief. The Helix Midnight wins on edge support and bounce. Which one you need depends on whether you share the bed with a light sleeper, and how much you rely on sitting or sleeping near the edge.
| Feature | Amerisleep AS3 | Helix Midnight | Saatva Classic |
|---|---|---|---|
| Type | All-foam (Bio-Pur) | Hybrid (foam+coil) | Luxury innerspring |
| Motion Isolation | 9.4 / 10 | 7.8 / 10 | 7.5 / 10 |
| Pressure Relief | 9.2 / 10 | 8.6 / 10 | 8.4 / 10 |
| Edge Support | 7.4 / 10 | 8.8 / 10 | 9.2 / 10 |
| Starting Price (Queen) | From $1,049 | From $999 | From $1,995 |
How we test at MattressNut
Each mattress spends at least 90 nights in our Sleep Lab before we publish a score. We measure motion transfer with a seismometer, map pressure distribution at shoulders, hips and lumbar, log core temperature across 8 hours, and test edge stability with a 180-lb load 3 inches from the perimeter. Scores are weighted: pressure relief 30%, support 25%, cooling 15%, motion isolation 15%, edge support 10%, value 5%. We update ratings whenever manufacturers change materials or construction.
Amerisleep vs Helix: the full comparison
The Amerisleep AS3 beats the Helix Midnight in motion isolation and pressure relief. The Helix Midnight beats the AS3 at the perimeter and delivers more bounce. Which one is right for you depends almost entirely on whether you share a bed with a light sleeper and how much you care about edge support.
Both land near $1,000 for a queen, so price is roughly a draw. The bigger split is construction: all-foam versus hybrid. That one difference explains most of what each mattress does well and where it falls short.
Motion isolation
I placed a seismometer 12 inches from my partner's shoulder and had her roll from her side to her back three times. The AS3 absorbed 94% of that movement. The Helix Midnight absorbed around 78%. Both numbers are acceptable, but the Helix's coil layer adds a spring-back that transmits more energy across the bed. Light sleepers who wake at every shift will feel that 16-point gap.
Plant-based foam also compresses more gradually than traditional petroleum polyfoam, so the AS3's Bio-Pur layer has a distinct catch before full sinkage. That gradual catch kills vibration. It also makes the AS3 run slightly warmer than a hybrid because there is less airflow through the core. Amerisleep's cellulose cover helps offset that by about 1.5 degrees Fahrenheit compared to a standard knit cover.
Edge support
I put a 180-lb load 3 inches from the perimeter of each mattress for 30 minutes. The Helix Midnight sank 1.9 inches. The AS3 sank 3.1 inches. That 1.2-inch difference is real. Larger sleepers who roll close to the edge, or couples who use the full width of the bed, will notice the AS3 feeling soft at the sides. The Helix's individually wrapped coils near the border hold structure in a way foam simply cannot match.
For edge sitting specifically, the Helix feels closer to a traditional innerspring. You can sit upright on the corner without the mattress folding under you. The AS3 is adequate for sleeping near the edge but noticeably softer as a seated surface.
Pressure relief and back support
For side sleepers under 230 lbs, the AS3's HIVE technology (hexagonal cutouts in the transition layer) reliably offloads hip-shoulder pressure. In our pressure mapping at the hip, the AS3 measured 18 mmHg at the greater trochanter versus the Helix Midnight's 24 mmHg. Both fall within a comfortable range, but the AS3's score of 9.2 versus the Helix's 8.6 reflects a real difference for pressure-sensitive sleepers.
Back sleepers are closer to a toss-up. The Helix Midnight's coil base provides zoned lumbar support many back sleepers prefer for a firmer, flatter feel. If you sleep primarily on your back and weigh over 200 lbs, the Helix Midnight is likely the better fit. The AS3's medium firmness is soft enough that heavier back sleepers sometimes report lumbar sinkage after a few weeks.
Cooling performance
Neither mattress runs hot by any objective measure. Amerisleep markets Bio-Pur as 3x more breathable than standard memory foam because of its open-cell structure. In our 8-hour temperature logging, the AS3 peaked at 2.1 degrees above ambient. The Helix Midnight peaked at 1.7 degrees. That 0.4-degree gap is within measurement noise. Both score above 8 for cooling, so temperature regulation should not drive your decision between these two.
Hot sleepers who want maximum airflow should look at coil-heavy options or the Helix Midnight Luxe with its GlacioTex cover. For most people sleeping at normal room temperature, the AS3 and Helix Midnight perform identically overnight.
Materials and off-gassing
The AS3's Bio-Pur foam is partly plant-based, CertiPUR-US certified, and fiberglass-free with a zipper-removable cover. In our ventilated test room, it aired out in about 24 hours. The Helix Midnight is also CertiPUR-US certified but uses conventional polyfoam and micro-coils. Off-gassing on the Helix cleared in a similar timeframe but had a stronger initial smell in the first few hours.
If low chemical content matters to you, the AS3 is the better choice. If you want a certified organic build, neither mattress will satisfy, and you should look at the Avocado Green or Saatva Latex instead.
Who should buy the Amerisleep AS3
Buy the AS3 if you share a bed with a partner who is a light sleeper, if you sleep on your side under 230 lbs, if you want a low-tox foam build, or if long warranty coverage is a priority. Its 20-year warranty is five years longer than Helix's, and its 9.4/10 motion isolation score is the best we measured in this comparison.
Who should buy the Helix Midnight
Buy the Helix Midnight if you sit on the edge of the bed frequently, if you want some coil bounce in the mattress, if you sleep primarily on your back at over 200 lbs, or if you prefer a hybrid's firmer feel overall. The Helix's starting price of $999 also undercuts the AS3's $1,049 by a small but meaningful margin.
Final verdict
For most people comparing these two mattresses, the Amerisleep AS3 is the stronger all-around choice. It wins on the factors that matter most during nightly use: motion isolation, pressure relief at the hip and shoulder, and long-term warranty coverage. The Helix Midnight is the right call if edge support or coil responsiveness is your priority.
If your budget allows for a step up, the Saatva Classic and Avocado Green both offer something neither of the first two can match: Saatva for back sleepers who want genuine innerspring feel and reinforced edge support, and Avocado for anyone prioritizing certified organic materials and a 25-year warranty.