We bought theses mattresses for our boys' bunk beds and they have been great. We knew that if we were going to put them on bunk beds, which aren't particularly comfortable themselves, we would need a quality mattress to put on them. Our boys are extremely happy with these mattresses. They aren't very tall so they work great with the top bunk and do not go over the rails. I have actually slept on the bottom bunk myself and I have to say it is better than my old traditional mattress was. By far! Comfort Extremely comfortable mattress. I like knowing that my boys are getting a good night sleep because they are on a quality mattress. Support If not using a box spring, I suggest putting down a piece of plywood to help with the support. If you do this, you will have no issues with sagging. Firmness I like a firm mattress and this mattress is exactly the firmness that i love. Durability When using this mattress for children, you will definitely need to place a waterproof pad on it. While cleanup is pretty easy, you don't want an accident to sink into memory foam.