From what I've seen and read, they both seem like great lenses... but I haven't shot with either yet so I can't say for sure. Wow, I'm a big help, lol.

are you looking to lay out the almost 900 for the sigma 1.4? if you are why not save up for a little while and laid down the money for the sigma 70-200mm 2.8 os ? that way you can cover your 85mm and then you can run the long end for other stuff and still have 15mm under that to play with as well?
the price differences is around 400 bucks











