We got the king topper and so far are very pleased for its cooling ability and the size meeting the expectations. We are exceptionally hot sleepers and struggled big time sleeping hot with our regular memory foam mattress, so adding the gel memory foam made a huge difference. The only thing we’re still not sure about is the “firmness” of the topper. We like our beds pretty firm and we’re sinking quite a big in this. But it’s not a horrible feel. It’s helped with some back pain for my boyfriend, but my neck pain continues to struggle so now I’m thinking to switch pillows and hoping that will help.