Samefly keeps saying IQ is most important. IMO, IQ is NOT sharpness and resolution alone. I recently also switched from zooms to primes only and it was purely based on the fact that for my eye, primes can have a "look" that is part of the IQ factor, and I think a lens can be less sharp than anther but have a better quality to the image.
The 135 is a lens that has that. If you go on the sample thread you will see it brought out by some. I am no where near the talent of some of the wedding guys that post there and kill it, but here are some of my samples with it I feel show some of that "look". The OOF areas in this lens are also worth noting as being unique.
IMAGE LINK: http://www.flickr.com …/stonemaster/11495462213/
IMAGE LINK: http://www.flickr.com …/stonemaster/11696878634/
IMAGE LINK: http://www.flickr.com …/stonemaster/11141472093/
AND the bird ones are with a TC at 2.8 wide open.....So if you already have a TC, or get one, you can make the 135 a very capable 189 2.8 as well.
Also, I know not a major concern with PP, but the 135 has ridiculous contrast and colors right out of the camera. I am not trying to be biased because I have it as what you get effects my life none, but I posted since I have one, and you also decided you wanted to get away from zooms, and maybe did so for similar reasons to me.
135 can be a **** focal length though sometimes, that is the only real drawback to this lens....That and it isn't 1.4