I recently began sleeping on my Serenity 3M waterproof mattress pad. I will start by saying that I have no issues with the fit of the pad. I have extra tall mattresses and it stays in place just fine. It is a medium weight pad and it adds a little padding between myself and the mattress. I am a uncertain of the quality of the product and the textiles used. The top of the pad is polyester and the waterproof layer reminds me of interfacing. The sides are made of a knit similar to tights. I have not laundered it,  so time will tell how it washes and dries.  All in all the quality seems to bother me.