This mattress has been a BIG disappointment! I've waited almost 4 months to write a review because I wanted to be sure that I was giving a fair review by giving myself time to adjust to sleeping on it. Believe me it takes time to adjust sleeping on it. I used my box springs but put plywood on top of them before putting the mattress on my bed. I am use to firm mattress and have slept on nothing else but firm for the past 25 years. But this mattress is more like rock hard. I'm glad I didn't order the extra firm. I can only imagine how hard it would be. As others before me have said the mattress is cut too large. It hangs over a std frame or box spring. I have NOT had any improvement in my sleep nor any relief for my aching back as others have claimed they've had with this mattress. For the price I suppose you may be getting your money's worth but I regret buying it and would NEVER recommend it to anyone!