I bought a memory foam mattress off ebay recently rather than a topper as I imagine they would shift (it cost me �200) I thought i would try it out and it is the best night sleep I have ever had. I can't help smiling when I get into bed as it is such a strange, but great feeling. They smell for a couple of weeks only. They are warm. We went for a medium to firm, but have recently lay on a soft, which is even better, but it is down to personal choice. They take a couple of weeks to get used to but I wouldn't go back to a 'normal' mattress again.