This 3" gel memory foam mattress topper is keeping me cooler than my previous memory foam topper - which was my first goal! The gel is heavier (more dense) than regular memory foam, but the 3" doesn't seem much higher because of the "egg carton" shape. This shape is not the same on both sides, so it is not reversible (shouldn't be an issue though). I was thrilled that it would come with a cover - definitely a selling point, but the cover did not look like what I was expecting. I thought it would fully cover the topper and would close with a zipper, but instead, it fits like a very large fitted sheet might, but goes under further. The cover is a bit clumsy to put on and have it fit over the corners and smooth out just so, but once you've got it on there, it looks and works just fine! Be sure that when you initially open the topper and unroll it on a flat surface to allow it to air out as long as possible (the smell is really strong at first- I let mine air out for 4 days), and this also allows it to open to it's full shape. Don't even attempt to put on the cover until you've got it in it's final resting place. I have been sleeping on it now for just about 2 weeks, and it really feels wonderful.