Our first sleep number lasted us 18 years. About a year and a half ago we upgraded to a higher end pillow top and love it.
My wife likes a very soft bed and I prefer firm. The sn is the only bed I know of that allows two people with very different preferences to be happy. In the past we were both compromising with other mattresses.
Imo, the characterization of them being cheap air mattresses is not accurate at all.