I have a THICK memory foam mattress/electric adjustable that I purchased at a home & garden show a few years ago - yup big bucks.  He promised me, no more hip pain, etc.  At first it was ok, but it's hard and I toss & turn from side-to-side all night.  Saw the rep at the show this year --- his explanation was I don't weigh enuf, but he would replace it with a softer model --- for $500!  I picked this mattress pad because it said the material helps keep it cooler.  Even tho, I would have liked a bit more padding to make it really soft, I LOVE it!!!  Plush and sleep all thru the night with no hip pain!!!!  I hope it keeps it plushness!!  I would definitely recommend!