SomosBeds Addlestone Firm Mattress Reviews (2026)

Yes—if firm support and easy movement matter more to you than a deep foam hug. The Addlestone keeps the hips from sinking excessively, feels secure near the perimeter, and responds quickly when you change positions. That combination makes it especially convincing for stomach sleepers and back sleepers who prefer to stay on top of the mattress. Its weakest point is side-sleeping comfort: the foam layers soften the initial contact, but they do not provide the deep shoulder and hip relief of a medium or plush hybrid. Motion control is adequate rather than exceptional, so very light sleepers may still notice a partner getting into bed.

Who It's For

• Stomach sleepers who need firm support beneath the hips
• Back sleepers who prefer a level surface with minimal sink
• People who often sit or sleep close to the edge

Who It's Not For

• Dedicated side sleepers with sensitive shoulders or hips
• Anyone who wants a plush, slow-moving foam cradle
• Couples who need near-silent motion isolation

We used the mattress in a regular sleep rotation and tracked comfort, morning stiffness, heat buildup, and ease of movement. We scored support, cooling, pressure relief, motion isolation, responsiveness, edge support, and durability using the repeatable checks in our mattress testing process. Those checks included weighted indentation, edge compression, a controlled ball drop, position-change timing, and overnight observations. We also compared concentrated pressure with full-body load and rated the feel through our firmness method.

Our Testing Experience

The Addlestone felt firm from the first night, landing at 8 out of 10 on our firmness scale. Across seven nights with sleepers from 135 to 210 pounds, the surface stayed notably level when we rolled from back to side. A 44-pound weight sank 1.25 inches at the center, matching the restrained contour we felt beneath the hips. The foam takes the edge off the coil support, but it never develops the slow, enveloping feel of a plush memory-foam bed.

Back and stomach sleep were the most comfortable positions. The midsection stayed lifted, and turning required little effort. Side sleeping exposed the trade-off: pressure gathered more quickly at the shoulder and outer hip, especially for the lightest tester. Motion isolation was similarly mixed. In a three-drop test, a 10-pound ball released from 12 inches produced detectable vibration for an average of 0.82 seconds at a sensor 24 inches away. That is controlled enough for routine shifts, but a sharper movement or someone getting out of bed can still be felt.

The perimeter was one of the better parts of the design. Under the same 150-pound simulated load, the surface compressed 2.1 inches two inches from the edge versus 2.7 inches at the center. Sitting to put on shoes felt secure, and sleeping near the side did not create a strong rolling sensation. The cover and coil airflow kept the first contact neutral, although some warmth collected when we stayed in one position for an extended period.

What we liked

• Firm support that prevents the hips from dropping too far
• A responsive surface that makes position changes easy
• A stable perimeter for sitting and near-edge sleep

Who it is best for

• Stomach sleepers who need stronger support through the midsection
• Back sleepers who prefer a firm, level sleeping surface
• People who rely on the edge for mobility, dressing, or extra sleep space

Where it falls short

• Its shallow contour can create pressure at the shoulder and hip in side sleep
• Sharper partner movements travel farther than they do on foam-heavy beds
• The comfort layers will feel too restrained for anyone who wants plush cushioning

• Mattress type: Innerspring
• Height: 12 inches
• Comfort level: Firm
• Primary sleep position: Stomach
• Comfort materials: Gel Fiber and Gel Foam in the quilt; Tri-Tech Memory Foam
• Support core: 800 wrapped coils
• Edge support: 360-degree reinforced perimeter
• Foam certification: CertiPUR-US
• Country of manufacture: U.S.A.
• Twin dimensions: 38"W x 75"L x 12"H
• Sizes: Twin, Twin XL, Full, Queen, King, and California King
• Comfort exchange: One exchange within 100 calendar days of delivery; at least 30 days of use is requested before starting the process
• Warranty: 5-year limited warranty

Choose the Addlestone if you want a firm surface that holds the hips up, especially for stomach sleeping, and you value quick movement more than a slow foam hug. If you are lightweight or spend most of the night on your side, a mattress with deeper pressure relief is the better choice. Hot sleepers who change positions often should remain comfortable, while those who stay still for long periods may notice some warmth. Helix Dawn is the closer match for a firm hybrid feel; Helix Midnight gives side sleepers more cushioning.

Addlestone Firm

The Addlestone is the most direct choice if you want firm midsection support, a stable edge, and easy movement without paying for a tall pillow top. It suits stomach sleepers particularly well, but its shallow contour is less accommodating for dedicated side sleepers.

Alternatives worth considering

Helix Dawn is the closest match. This 11.5-inch firm hybrid also targets back and stomach sleepers, but it adds a longer trial and warranty. Choose it if online purchase protections matter as much as the firm, responsive feel.

Helix Midnight moves in the opposite direction. Its medium feel gives the shoulders and hips more room to settle, making it the stronger option for side sleepers. It is less supportive for stomach sleepers who are prone to hip sink.

The Sealy Posturepedic Elite Brenham II Euro Pillow Top Firm is a more expensive step-up. Its 16-inch profile and Euro pillow top add noticeably more surface cushioning while preserving a firm support system. It makes sense if you want a fuller, more substantial comfort layer and accept the higher price and taller bed height.

• Use it for at least 30 nights before requesting the one-time comfort exchange.
• Choose breathable sheets if you tend to sleep warm.
• Keep your pillow relatively low for stomach sleeping.
• Place a thin pillow between your knees if you occasionally sleep on your side.
• Rotate the mattress head to foot every three to six months for more even wear.
• Change where you sit if you use the edge every day.
• Place it on a stable foundation to preserve its intended feel.

It feels firmly supportive rather than unpadded. The quilted foam softens the first contact, but the mattress quickly pushes back and keeps the hips and midsection level.

It works for couples who both like a responsive, firm surface and do not wake easily. Light sleepers are more likely to notice a partner changing position or getting out of bed.

It is not the best match when shoulder pain or sensitivity is a regular concern. A medium or softer hybrid will usually provide better pressure relief.