I replaced my old 4 inch memory foam topper that had worn out with this, and I like this one much better! Ok, it took me 2 hours to get the layers into the mattress cover the first time, but the effort was well worth it. I'm sleeping like a baby and don't notice when the dog jumps in and out of bed overnight. Highly recommended. Oh, and it perfectly fits my mattress. The last one I had was 4 inches short on the top and 2 inches short on each side.