I love this mattress. I WAS sleeping on a hybrid style mattress for about 6 years that began to sink in the middle. My husband and I have been wanting to try a memory foam mattress for a long time, but were inhibited by the price. When I saw this one for such a great price and read the reviews, I figured we could give this one a try. When it arrived, I was a little concerned because it was so thin. We left it expand for 24 hours before we slept on it. We simply placed it on top of our old box spring foundation, and we were amazed at how firm, yet comfortable this mattress is. We both have bad backs, and my husband tossed and turned on our old mattress. If he is tossing and turning on this one, I cannot tell because there is no bounciness like we had in our old one. We are also able to get up out of bed much more easily. I would definitely recommend this mattress to anyone that prefers a firmer sleeping surface.