I have a close friend who was having some back problems which she thought was due to an older mattress so she bought the tempurpedic classic on the adjustable frame and absolutely loves it! She says her back problems are gone, and the adjustable frame also has a built in massager!
Also, buy the sheets they have at the store made for the bed, along with the water proof mattress protector (protects your pricy investment).
And, it may take a little while to get used to for some people but for my friend, there was no long adjustment time, but there was a bit of an odor at first, but it does...