I am glad i got firm and 10 in. I'm 6'3" and just under 200 pounds. I sleep great on my back and even stomach on occasion. This may be too firm for some side sleepers but i knew that beforehand and it isn't uncomfortably firm. The only small complaint i have is getting some of my queen sheets and bed liners to fit as it feels larger than the dimensions listed. But overall, great nights sleep and the cooling gel effect is awesome when you first lie down on it :)