Puffed up almost immediately, and was able to sleep on it within a half an hour. It had a slight odor to it, but that dissipated quickly (less and an hour). Super easy to open, and they even included a little tool to cut the plastic. Has holes for improved airflow (which you may need as this is SOFT) and you can feel the air moving when you turn over. You do need deep pocket sheets when adding this to your bed, and it doesn't quite cover the entire top of the mattress (but that's good because then it won't shift when your sheets do). Basically like getting a brand new memory foam mattress for 1/8 of the price. Will DEF buy again!