My wife and I both have back problems, and wake up several times during the night.  In the morning my wife can't stand up straight until she "warms up".  After the second night, my wife realized that she had slept for 8 hours straight, both nights!  She couldn't remember the last time that happened.  We are both loving this mattress.  Definitely worth the price.

Pros: Delivery on time.  Everything went perfectly.
Cons: not a one!