I don't have the 100L, but I do have the 100 non-L macro and the 135, so it is sort of the same principle. The difference is, I do shoot macros a fair bit, I also like narrow depth of field, so I never considered getting rid of either of them when I got my 70-200 MkII a couple of months ago. The reason I got it, was artly due to travelling, as it allowed me to travel with less lenses. On thursday, I went out with a friend and her twins and took along the 70-200 to use, but guess which lens I also took, in case I got the opportunity for selective focus? Yep, the 135L. As it happened, that sort of shot isn't really possible for toddlers when they are running about and I didn't even try to use it, but I felt better knowing it was in there. For more standard portraits, particularly actions shots, the 70-200 is probably the one to go for and the 135 won't really be needed, but if you want more artistry, then the 135 is the one to pick up. If you do a mixture (which from some of your work you do), then both will be handy. Also, the 135 gets close to true macro if you use the full Kenko set of extension tubes, so you still have close-up capabilities, even with the Canon set or a single tube, allowing you to dispense with the 100L.