I bought a firm mattress which turned out to be too firm. I bought this mattress topper with cover, and I could not be happier. I was going to buy a sleep number bed until I spoke with a couple of people who had sleep number beds and bought a memory foam mattress topper in addition. I decided to buy this mattress topper and my husband and I are sleeping much better, we wake up without the back pain, the evenly distributed support works wonders. This is a very worth while investment.