This one is a winner! We got it and immediately my son was like how is this going to be a mattress since they vacuum seal it so we'll.  It took seconds for it to go to its natural form and we let it sit for about an hour maybe 2 hours before we put it on the bed, and even in that time it was toddler tested with jumps and I even laid on it and it was very comfortable.  My son who it was for, said it was the best night sleep, very comfortable.  My daughter now wants one.