That is a great deal on the 35.
I took the rented 18-35 on a trip to Chicago and shot roughly 500 pictures, 300 of which were keepers. I haven't processed any of them yet, as I'm waiting for Lightroom to release a lens correction profile.
My copy seemed to hunt a little, especially in low light. Keep in mind I shoot on a 60d, so not the greatest autofocus to begin with. I did like the range a lot; I have a 17-40L so this was pretty close in terms of focal lengths.
I've been thinking a lot about switching to full frame, and thought maybe this lens would convince me to stay with crop. No conclusion so far. I wanted to love this lens, and I still could, but I won't know for sure until I get a chance to process all my shots.