The Mammoth HealthPRO Optimum Mattress is the softer, deeper of Mammoth's two all-foam HealthPRO models, and it's for side sleepers who want a cushioned foam bed and don't overheat. Everyone else should look at the sprung HealthPROs. Strip away the trademarks and this is a stack of foams under a quilted top, which can make a perfectly nice bed, but Mammoth's health-heavy naming claims more than foam can do.
A softer high-resilience foam where the Precision has a firmer one
On top is the same 60mm zoned layer of Mammoth's Medical Grade foam, cut into PostureCells, then an AdaptPro support foam. Where the Precision uses a firmer reflex foam, the Optimum has Mammoth's Premium Reflex, a high-resilience foam Mammoth describes as softer. It's 31cm deep, with a deep quilted top and a carbon-infused WAVE fabric, and Bensons sells it in Medium and Firm.
High-resilience foam is the better kind of foam to my mind, because it springs back faster than memory foam and doesn't trap you as much. Even so, 31cm of foam with no springs in it will sleep warmer and feel more muffled than a sprung mattress. Expect a plush, even surface that cushions the shoulder and keeps a partner's fidgeting off your side.
Measure your fitted sheets first. Past 30cm a standard sheet stops reaching round the corners, and this is 31cm before you add a protector.
Side sleepers who run cool, and nobody who runs hot
Light and average-weight side sleepers who choose Medium are the match, since a soft foam top over zoned support lets the hip and shoulder sink a little. If you and your partner sleep still, you'll like how little movement crosses the bed. No owners have reviewed it yet, so the build is all you have to go on.
Avoid it if you sleep hot. Avoid it if you're heavier than about eighteen stone, because an all-foam stack gives a heavier body less to press against than a good spring unit. Avoid it if you sleep on your front, where a soft foam top lets the hips sag. And don't buy it for the Chartered Society of Physiotherapy partnership on the label: that's a tie between the society and the brand, and it says nothing about which Mammoth suits your body.
What to buy instead
Choose the HealthPRO Precision if you want the same foam idea with a firmer middle layer and less depth. Better, choose one of Mammoth's pocket-sprung HealthPRO models, which is where I'd put my money in this range, because springs underneath give you airflow and lift that a foam stack can't.
