Despite the name, the Hypnos Cawthorne Deluxe Mattress is the plainest bed in the Cawthorne range, with the fewest springs listed and no natural fibres. It's still a decent medium mattress from a maker I rate. Buy it for an average-weight side or back sleeper, a spare room or a first proper bed. If you're heavier than about eighteen stone, or you sleep hot and want wool or cotton next to you, buy something else.
The Deluxe is the bottom rung of the Cawthorne range
Inside are 1000 of Hypnos's ReActive pocket springs, with firmer springs in the outer rows and a rod edge to stop the border collapsing. Above them, top down, are Solotex fibres, a layer of Hypnos's eOlus fibres made from recycled material, and a dual density polyester pad, all tufted under a Belgian damask cover. It's 25cm (about 10in) deep and one-sided, so you rotate it rather than flip it.
Set it against its siblings and the name looks cheeky. The Cawthorne Luxury has the same Medium grade with 1400 springs, wool and cotton. Even the Firm Support gets 1200 springs and cotton. A thousand pocket springs is a little light for a double, though they're pocket springs, so it's still a good way to be held up. Check the Luxury's price before you buy this one, and if the gap is small, put the money there.
Medium on the label, a bit firmer in the bedroom
Owners mostly keep it short and happy. When they do talk about firmness, more of them found it firmer than a medium than softer: one found it "a tad firmer than I expected", a side sleeper added a topper to soften it, and an owner in their mid-fifties swapped it for something with more give at the hip and shoulder. A couple of others thought it soft. I believe the owners over the label here, so expect the firm side of medium.
That suits back sleepers and couples. It's also why a lighter side sleeper should go softer. If it's only a touch firm for you, a topper is the right fix, because a topper solves too firm and never solves sagging. One owner with arthritis found the surface too bumpy, which I'd put down to the tufting. Some of the older reviews are for the earlier Hemsworth Deluxe, which on paper was the same bed.
Fibres, not wool, so think about heat
Solotex is sold as breathable, and fibres of any kind sleep cooler than memory foam. I still like a natural fill next to the skin for anyone who runs warm. I'm fussy about what touches my skin anyway, the kind of sleeper a scratchy label bothers. If you run warm, the Luxury's wool and cotton are the better bet.
Avoid it if you're heavy, if you want a mattress you can turn, or if you want the medium grade to settle an argument between two of you. Mattress Online sells the Medium grade as a compromise for couples who like different firmness. In my experience a middle-ground mattress leaves you both slightly unhappy. Two different grades zipped together beats it, so ask whether you can pair two different Cawthorne singles as a zip and link.
What to buy instead
Buy the Cawthorne Luxury if the price is close: same feel on paper, more springs, and wool and cotton on top. Back sleepers who like a firm bed should take the Cawthorne Support. For a spare room on a tight budget, this one will do nicely.