I bought this mattress in a twin size for our guest bedroom. It's not often used and so fat, two guests have said it's pretty comfortable.
My only drawback in giving it 5 stars is because it dips at the sides, but then , it's not made w/the sturdiness of a standard mattress sine it's all foam. There is some chemical odor that dissipates within a week or so (it also comes wrapped in a soft zip liner that probably helps mask the odor and is a nice addition anyway).
I recommend it and would say that you can't beat it for the price and ease of assembly. It fluffs up to its full size over a couple of days. Fits a standard sheet nicely!