I have one. I'll try to remember to post some pictures later this week.
I have the 135 f/2, the 70-200 f/2.8 IS, and the 85 f/1.2. I love all of them for different reasons. Compared with the 70-200, the image quality is noticeably better (it is a prime, after all). It is also much, much smaller and lighter. Having the extra stop can also be a big help in low light.
It also have several advantages over the 85mm. It feels more balanced (the 85 is kind ungainly). It focuses much faster. OK, you could say that about any AF ever made compared with the 85mm, but the 135 really does focus quickly. Overall, the image quality is on par, especially once they are both at f/2.8 or lower.
I bought the 85mm and was given the 135mm at roughly the same time. I had always wanted the 85mm and wasn't all that interested in the 135mm. Now that I have both, I think I use the 135 about 2 or 3 times as often as I use the 85mm. It has become one of my favorite lenses.