Apples and oranges
The 100mm doesn't have a 'zooming ribbon' cause it doesn't zoom.
Having said that. I am one of those burnt (twice now) by the 24-105L's damned ribbon. Without this issue (actually, it is actually more about Canon's refusal to own the problem they MUST surely as day know about), I would have no hesitation in recommending this lens.
However: the issue has arisen; Canon is not owning the issue so, I have to say that I honestly couldn't recommend that lens to you.
So, maybe the 100L or the 24-70L.