The Best Split King Mattresses

Sitting-edge compression measured 2.21–2.29 inches, and stability while lying near the edge was outstanding. The foam encasement keeps the perimeter exceptionally secure for sitting, sleeping near the side, and using the full mattress width.

Sinkage measured 1.99–2.07 inches on an 11.50-inch profile. The Lumbar Zone design and two coil layers provide additional structure through the center third of the mattress, producing the lifted support reflected in the alignment assessment.

The surface mostly recovered in 0.196–0.204 sec. and fully recovered in 0.39–0.41 sec. Bounce measured 12.28–12.78 inches and sinkage measured 1.99–2.07 inches. Those results match the easy-repositioning experience described by many owners.

The hybrid airflow, copper-infused foam, Celliant cover, and optional CoolForce layer give the mattress multiple heat-management paths. The deep 2.61–2.71-inch sinkage means body contact is still part of the feel, so owner heat-retention comments matter. The final 9.5 rating reflects that added surface contact.

Pressure maps were excellent: side-sleeper average/max pressure was 0.108–0.112/0.67–0.69 PSI, back was 0.059–0.061/0.49–0.51 PSI, and stomach was 0.078–0.082/0.53–0.55 PSI. The 5.0-inch comfort layer and 2.61–2.71-inch sinkage explain the deep contour, while owner comments keep the firmness-choice caveat in view.

Response timing showed mostly recovered in 0.39–0.41 sec, and fully recovered in 0.98–1.02 sec. Bounce measured 10.49–10.91 inches, so the bed has enough lift for repositioning even with 2.61–2.71 inches of sinkage and a thicker comfort system.

Motion-transfer testing was exceptional, with peak-to-peak acceleration of 2.07–2.15 m/s². The all-foam build and low 6.58–6.84-inch bounce help quiet partner movement, though that same muted feel is less responsive for sleepers who want spring.

Pressure-relief testing landed at the top of the range. The 2.12–2.20-inch measured sinkage and 6-inch comfort system fit a medium foam surface that gives shoulders and hips more room than AS2, while owner fit reports keep the pressure-relief guidance focused on side and back sleepers.

The AS3 has moderate 2.12–2.20-inch sinkage, a 12-inch profile, zoned transition foam, and quick enough recovery for many side and back sleepers. The medium feel and low 6.58–6.84-inch bounce are the reasons stomach sleepers and heavier bodies should compare firmer builds.

The tested mattress measured about 11.00″ thick with roughly 5.25″ of comfort material and a 6-inch organic latex support core. Owners report both lasting comfort and later durability concerns, making correct foundation support, rotation, and layer care important.

The surface mostly recovered in 0.196–0.204 seconds and fully recovered in 0.29–0.31 seconds, while bounce measured 7.54–7.84″ and sinkage measured 2.63–2.73″. The all-latex construction regains shape before the deep cushioning can hold a combination sleeper in place.

Cooling testing scored about, sinkage measured 2.63–2.73″, and the current construction uses organic cotton, wool, and latex. The breathable materials offset some of the additional body contact created by the deep contour.

Sinkage measured 2.59–2.69 inches on a 14-inch profile. That result was assessed alongside the official medium-firm feel, hybrid support system, zoned-lumbar layer, and the position- and weight-specific fit results.

Sitting compression measured 2.69–2.81 inches, and lying edge support was rated outstanding. The final rating reflects those results and the 14-inch hybrid construction.

Official policy sources list a 120-night trial, 30-day minimum, $99 mattress return fee, one comfort-trial occasion, free direct shipping, and a limited lifetime warranty. The return fee and one-trial limit keep the protection below the top bands.