Salespeople told me that they really don't make mattresses much anymore that require a box spring underneath. Newer mattresses usually have several layers of stuff inside them, different foams, ect. I got a temper pedic one with one of the movable bases so I can raise my head a bit as I have gastric reflux. I love it. I also opted to get the one with the "cooling technology cover" as foam mattresses can be hot to sleep on. I paid more for this mattress then I ever did before. I have been sleeping on it for about 4 years now and it is the most comfortable mattress I have ever slept on. I have fibromyalgia and my pressure points don't hurt, I also have a bad shoulder and again, it is comfortable for me. I did try it out in the store for about 15 minutes but you really can't tell until you have tried it for a few nights. I had bought one with firmer support first thinking that was what I needed, but it came with an exchange provision, and I did trade it back in for the one mentioned above as it just was not comfortable. Oh, and I also measured the height from the floor when I got it as I did not want to have use a step to get into the bed.