This is our first memory foam mattress, and we are so impressed.  My husband and I are both quite heavy, and this bed can take our combined weight with no problems. I have back pain, and while it is not totally alleviated, I can sleep without waking to change positions. I have never been able to sleep on my side before, as it was too much for my back. I now sleep very well on my side, and my husband sleeps comfortably on his stomach.  It expanded to full size within a few hours, and we have been sleeping soundly each night since the day it arrived.