I read the reviews and decided to go for it, even though I had never bought a mattress online. Note to self: Never buy a mattress online again! When you get it, it comes vacuum-bagged, once you open the plastic bag you WON'T be able to return it. Once open, you can's sit or lay down on it because it sags. If you are on one side of the mattress you will inevitably end up sunk in the middle of the bed. I called customer service and they said this was normal, they told me to wait for 48 hours until it was fully aired. They also said that if I was still dissatisfied with it after the 48-hour window they would gladly return it....NOT true. I waited for it to "air" with hopes that it would behave like a normal mattress.... it didn't. Called back and was told that since the mattress had already been aired it would be hard to get a return. I was also told to take pictures and send them to the "mattress department" who would ultimately decide whether the mattress was defective or not. After all the claim was written and the pictures were sent the response was: We apologize for the inconvenience but the item cannot be returned, it is not firm because you bought the medium firm version not the firm one. Does that mean that medium firm mattress won't hold your weight? The problem with this mattress (at least with the one I got) is the construction, not the firmness. Mattresses are not supposed to sag like deflated air mattress. My advice is: do not buy it, you will end up throwing away your hard earned money.