Due to budget constraints that I have, I use this a my major lens. It is never off my camera and I really get on well with it.
Barrel distortion is evident, but only at the extreme.
I have no real complaints and have produced what I would consider some nice shots. In fact most of the shots you will see from me on the forum are taken with it.
Much like CT I have been looking at the 17-40, as I do mostly landscape. But in my books the 17-85 comes highly recommended.
It not too heavy and gives a reasonable range. Cheers, Neil