Its really lovely and comfortable. I dont get the sensation of sinking into it, but I do get a really cradling sense of comfort. My knees and shoulders and hips do not ache as they did. 

It is slightly warmer than not having a topper. I took off a blanket and Im fine. I actually enjoy being slightly warmer, as I also like the white noise of sleeping with a fan on. If you are a very warm sleeper, it might not work for you.