I read all the reviews - it's not like sleeping on a cloud, but it does add a lot of softness and comfort to my 3-year old mattress from Sam's Club. It isn't hot or lumpy or anything negative - I will change that if I wash it and it gets lumpy and unuseable. I let it sit undisturbed for 48 hours like the directions recommended and it did seem to 'puff up' a little more -- all I know is that for the price, it's pretty amazing and pretty nice to have on my bed. I'm very happy with it so far.