The mattress is very light and springy. The bed is short, but not insanely so. People over 6' are probably going to have more problems; people approaching 6' are likely to be able to make do with it as a guest bed. I wouldn't want it to be my primary bed but I could see spending a few nights on it without any significant complaint, and it's a fully functional size for kids.
There are two cross-bars under the bed. The one toward the head of the bed drops down slightly, so that when you're on the bed you shouldn't actually press into it. The lower bar where your legs would be gets less pressure, and in a quick test I didn't feel that bar. So all in all, the design is pretty clever.
Last edited by aaron; 12-04-2010 at 12:30 AM.