Canon 'walkaround' lens

Currently I have the 17-55 f2.8 IS. This has a L lens quality and I'm pretty much satisfied with the focal length range. My friend has the 28-135 IS lens and he stands by it. Saying he can't live with anything under 100.

Both of us use crop body. He a 50D and me 7D. I was wondering what is the general opinion, would you guys settle of a better lens with a shorter FL range?