I bought a Sleep Number bed 4 yrs ago (the dual control type). I noticed I started waking up with terrible back pain and it took me a while to realize it was the bed and that even at the highest air level of 100, it was in no way firm or supportive enough to support or conform to my spine. It was only when I noticed after sleeping at hotels or staying with friends, that I was NOT waking up with unbelievable back pain like I did at home. I work out for over an hour 5-6 times a week so anyone who tries to blow off these complaints by saying that they user's back hurts because they are just out of shape, is dead wrong.
I ended up having to have back surgery to fix hernited disks that I feel had been caused by the years of sleeping on this bed with NO support - leaving my spine to sag along with the mattress. I actually avoided fusion of my spine simply by changing to another type of high quality/ firm mattress.
If the Sleep number bed would allow people to inflate it MORE to say 180 or so, they might be able to offer people better support. But for those of us who need more than 100 (top air level), this bed is frustrating, limited and expensive when you add up all the medical bills. I do have to say it is a -itch to put together too by they way.