I'd talk you out of the Silentnight Miracoil Memory Cushion Top Mattress, because it puts two things I avoid into one bed: a sewn-on top tier and a linked coil spring unit. The memory foam sits inside that separate top, over Silentnight's Miracoil springs, and the whole mattress is graded Firm. If you're a light sleeper sharing a bed, or you want a mattress that wears evenly for years, look elsewhere.
The cushion top is a second tier stitched on
Mattress Online's photos show what "cushion top" means here: a quilted panel with its own piped border, sewn onto the main body of the mattress like a lid. That's a box top in all but name. Inside it is a layer of memory foam, then densely packed polyester fibre above the springs, all under a knitted, micro-quilted cover. The listing never says how thick the foam is. Ask Mattress Online before you pay for a foam top, because that's the one number that tells you how much cushion you're getting.
My problem with any top tier is how it ages. It takes your weight every night and softens fastest, so it tends to take on your shape before the springs underneath have done much at all. On a one-sided mattress there's no turning it to share the wear; rotating head to foot is all you've got. Memory foam also holds warmth. Skip it if you already kick the duvet off in winter, because a foam top is the wrong place to start. Silentnight's naming habit is in full flow too, with three selling points in one product name and none of them telling you which part wears first.
Miracoil is Silentnight's own take on open coil
Miracoil springs are made from a continuous coil of wire, and Mattress Online files them as Silentnight's open coil system. Silentnight zones the unit in three, with more support under your hips and lower back. Zoning is a sensible idea, though it only helps when the zones line up with your body, and a tall or short sleeper can land in the wrong one. A linked unit also passes movement across the bed. My partner turns over all night and steals the duvet on the way, so a mattress that hands every one of those turns straight to my side is one I wouldn't buy.
At 25 to 25.5cm deep (about 10in), most fitted sheets will still go on. Check the turn on your stairs before delivery day, as it doesn't arrive rolled.
The old reviews call it firm, and the new foam top is an unknown
Nearly all of the reviews here were written about the Silentnight Seoul Miracoil Memory, the flatter mattress this listing used to sell, with a thin memory foam layer and no separate top. Firmer than expected is the complaint that comes up most among those owners, usually with the foam barely felt and sometimes a topper bought to soften it. One wanted "a thicker layer of memory foam". After that come movement across the bed and some spring noise, and the happy owners mostly liked a firm feel for their back.
The cushion top should feel softer at the surface than the old flat top did, but the listing gives no foam thickness to judge it by. Read Mattress Online's comfort trial terms before you order. When I checked them in October 2026, the trial offered an exchange rather than a refund, and only if you'd bought one of their mattress protectors with the mattress.
What to buy instead
Buy the Silentnight Memory 800 Mirapocket instead. It keeps the memory foam but puts it over pocket springs that move one at a time, and it's graded Medium to Firm, a notch kinder to a side sleeper's shoulder. If price is what brought you here, a plain pocket-sprung mattress with fibre fillings will outlast a foam top on a linked coil.
