I don't have the 100L but I do have the 135L and it is a must have lens IMO. The 100L is a macro so I would not compare them I would just consider them for different purposes. I do have the 70-200 f/2.8 II and while it is an excellent work horse lens, it is not the same as the 135L. I use them for different purposes as well and I need them both. The 135L is very light and easy to use as a walk around lens.
135L examples with minimal editing...
Darn! I dunno what to say but these are some of the best photos I have seen in recent times. Did you get these colors and contrast right off the bat? Please say yes! =O