After considerable research I bought the 4 inch queen. I am over six foot and 200 lbs, have had back surgery am over 70 with a bad knee and sleep hot. The positive is it definitely provides the support I was hoping for. It is not a “plush” type topper. Not exactly firm but for me and my size it’s just right. It has helped my aches and pains. It’s not as difficult to turn over as the plush type toppers. However the  main negative is it sleeps HOT. I have been able to control it to some degree by removing a blanket and only using a sheet to cover myself with. It will take me some time to work out what I need to do to keep me comfortable enough at night so it don’t wake me up.