I've had this topper for about a month now and I must say that it was the best purchase decision I ever made. After suffering for 2 years with aches and pains from 5 new, top of the line mattresses that sagged and dipped, I exchanged my last luxury pillow top for a firm memory foam matteress which is so firm, I'm sure it will never sag. We put this topper on top of the mattress and it is perfect! I now sleep through the night and wake up with no aches & pains. Ok so there is a little bit of a chemical odor at first but it goes away quickly. I had no problems with the size or thickness of the topper. I also found that it is a bit hot but i now turn the AC down a knotch and it is not an issue. Regading the size comments, I found that if you gently pull on the sides, it stretches to cover the entire mattress. I bought a hotel quality mattress cover from Sears which makes the mattress pad look like a finished mattress. I was so please whith this product that I purchased a second one for the guest bedroom. If you suffer from aches and pains and wake up several times from tossing and turning, you will definitely love this topper!