We have a 3" memory foam topper and it makes the bed very comfortable. If you buy one, pay attention to the density of the foam - heavier is better and it should be breathable foam so it doesn't make you hot, or have the cool gel layer. Cheap is not better. These ARE NOT the $20 crate foam tops. We purchased ours at Sam's Club approx 8-10 years ago for $170 queen size. We did not cut ours off, rather the regular queen fitted sheets fit and it just folds down over the bottom of the mattress. I flip the end up and over onto the bed when we put the slide in to travel.