I cannot say how much I love this mattress! I was a little hesitant as it's the first time I have purchased a foam mattress, but I was extremely pleasantly surprised. It fully expanded within about 24 hours, but I left it for 48 hours as instructed. There was a slight smell upon opening the package which concerned me, but it dissipated within the first 2 days. I'm very sensitive to smells and have gotten a migraine from sleeping on a memory foam pillow that smelled previously so was initially concerned but have had no problems at all with this mattress. It's quite firm but I'm a stomach sleeper so this works for me, and I haven't had any back pain from lack of support since sleeping on this mattress.