This is a really good quality mattress for the price. It expanded very quickly and with no issues. I did leave it out to fully expand for a couple days after unpacking it just to be safe, but I probably could have slept on it that same night. There was no odour whatsoever. This is definitely a FIRM mattress. For me it was a little too firm, but I figured it would be better to get one too firm than too soft - you can make a firm mattress softer, but good luck making a soft mattress firmer. I added a 2-inch memory foam mattress topper and now it's absolutely perfect!