I like these because in the summer the "bumps" allow more airflow which reduces the overheating - but in the winter when you want to stay warm you just flip it over to the flat side. The downside is that they do compress, so it's helpful to have a foam pad under them for extra cushion and support, no matter which side is up.
This memory foam mattress is terrific. You feel like you are sleeping on a cloud. This is my first "Serta" memory foam mattress, and the second mattress that I have ordered from Overstock.com. Both experiences with the products has been very good.
We were in the process of purchasing a new mattress and instead saved money by purchasing the gel mattress topper. It is the most comfortable sleep that we've had in months. I am so comfortable and supported through the night that I no longer toss or turn to find a comfortable, SUPPORTED position. I would have rated the topper 5 stars, however, I feel that it does not cool the body as I had hoped or read in other reviews.