We bought this bed trying to find something cheaper that we could get then buying a tempur-pedic mattress, and I was very surprised at the pricings for these mattresses. It only took a few hours for it to expand to its full size, and we were able to sleep on it the same night. There was a odor on the matrres from it being packaged tho, and it was pretty strong to me, but it faded within a few days. We were a little surprised at how firm this mattress is, as we were expecting it to be a little more conforming(this is the only reason I rated this a 4 star), but it is still a great mattress. We get much better sleep then we did with our old mattress by far. We have also noticed that it holds in body heat too, and this can make it a little warmer then you might be used to while sleeping. For us it isn't a problem, we just turn on the ceiling fan and we are balanced back out. I read some of the reviews on this bed before we bought it and read how their back pain was completely gone after buying this bed, it wasn't like that for us and it still isn't like that. We don't however, have as much or severe pain as we used to so it does help a little, but not exactly as we thought it would from the reviews. It is a great mattress reguardless, and I would definitely recommend it to others if they were looking for a firmer memory foam.