It is amazing how the mattress is shipped and actually began expanding as soon as i begin cutting the plastic. It did have a slight chemical smell, but it was not strong at all. I waited almost 48 hrs to sleep on it. It appears to be an excellent mattress. I am sleeping like a baby. I got the king medium firmness. At first i was thinking it was too soft but I got firmer after a few days. Seems like it get firmer after you sleep on it a few days. I love my mattress. I only gave it a 4 star because i have only had it for two week and not sure yet how it will hold up. But for less than $300, if it only hold up for a couple of years, i feel like i got my moneys worth. It feel like a quality mattress and i think it will hold up for at least 5-8 years, which is normal nowadays.