Purchased the BODIPEDIC a few months ago. My wife is hard to please when it comes to mattresses. At first she did not like it. She said it would sink in the middle. The answer is simple, it's the box spring. I have a excellent box spring but BODIPEDIC'S do not work well with box springs. To correct the problem just put a sheet of plywood between the bed and box. It firms up the BODIPEDIC. My wife told me that solved the situation. She gives it a 5 star rating.