I recently got the Sealy 10" Memory Foam Mattress-in-a-Box and I am so happy I did. The package arrived and you think to yourself how in the world is my King Size mattress in there! Well you open the box and following the instructions and in just a short amount of time you have a big mattress out of that smaller box! The mattress comes to it's full size with in 48 hours and I must say ours was super comfortable on night one! The memory foam conforms to your body making you feel supported yet so relaxed! My back has been feeling less stiff with just a few nights use. With Sealy this mattress is not hot at all like some memory foams tend to get. I am not waking up hot or uncomfortable at all! Sealy has gotten a life long customer!