Fantastic mattress - pretty deep, so i'd suggest making sure you buy at least "deep" and maybe even "extra deep" mattress protectors/sheets with this. It's very comfortable indeed, i'm a big guy (!) And need a very firm mattress, and this is well up to the task. I could comfortably sleep on this in any position, including flat on my back (which normally leaves me waking up in the night with a stiff lower back) without any problems. Highly recommended if you want a firm mattress!