This is the first time we have tried this type of mattress, we did lots of research and made this our final choice.  The mattress arrived on time, actually a couple days early, it was not in a box, but did come in a duffel style bag with handles, no paperwork, and the bag had a tear, so we were a bit skeptical as we were not sure this was what we ordered.  We set it up, the mattress expands very quick, and we did allow it to set over 24 hours before using.  My husband liked the mattress right away, it took me about four days, now I am sleeping much better and really like this mattress.  The mattress is firmer than I was expecting, that may be what took me longer, also we both noticed that we don't wake up sweaty, the cooling gel really works.  We are very happy with this purchase!