I was in need of a replacement for a worn-out memory foam mattress. I was pleasantly surprised by the thickness of the mattress, and the base is really sturdy. Given that, I was expecting it to be a little firmer than it is, but it's still quite comfortable and not a mattress you sink to the point of getting lost in! It reached its full thickness quickly and there was a little off-gassing the first day I opened it, but the smell was gone by the next day. My standard twin fitted sheet does not quite stretch over both sides of the mattress, but that's okay - a good excuse to buy new sheets, too!