I own a tempurpedic mattress, which is at my house. I however live in a dorm room for most of the past few years, so I sleep on the bed that is provided.
To be honest, I really can't wait to get home and start sleeping on the mattress. The mattress is like a baseball glove. At first, the mattress may feel uncomfortable or harder than you would like, but after you "break in" the mattress it is wonderful.
The thing I like most about the mattress is that I can sleep on my side, which is my preferred method of sleep. When I sleep on my side in the dorm room, I find that my ribs tend to hurt or pressure on my arm that is not present when I sleep on the mattress.
I am a young fellow (21 years of age) and I am slender in profile, so I can't comment about how it may affect severe back pain or anything like that, but the bed is definitely worth it in my opinion.