With all the 5-star reviews, this seemed like a good deal. However, after unpacking the mattress and letting it off-gas for a couple days, we put it on our bed, and it had a noticeable depression across the middle of the bed. It is very uncomfortable to lie on. Also the memory foam does not really behave like that in the stores; it feels more like regular foam. In short this has been an expensive lesson, as the mattress cannot be returned. I may take this up with the manufacturer, as this is probably a factory defect. I may have to check my consumers' rights here in California if I cannot get a refund or a satisfactory replacement. So, I recommend purchasing a mattress with a warranty, or from a local store, and avoid web sites that say "All Sales are Final".