I needed a new mattress and decided to switch from spring to foam. I had a difficult time deciding because I couldn't actually lay down on the mattress. After reading all the reviews I decided on this bed and couldn't be happier. I use it on a platform bed without a box-spring.. I'm sure either way would be just as comfy. Mattress gets a little softer over time (but in a good way) its not to hard and not to soft. Since my purchase my mother has also purchased the same mattress because she laid on mine and fell in love.