I got my Ultimate about 5 years ago. I use the X-Strap all the time because my back has been going bad. I've never run out of space - once delivered some dude's monster of a Mac G4 desktop computer down to CompUSA for repairs. Now I commute to work with it -shoes, pants, shirts, lunch, etc. Every once in a while I think about getting a smaller bag, but with all the compression options, I don't really see the point. I've been super happy with it.