The 17-40 is rubbish, and the 16-35 is more of a workhorse for photojournalists. Sharp at the center but lousy edges and corners.
That's a mighty big call to say the 17-40 is rubbish. Maybe you have not owned one. It's mushy wide open but is a match for the 16-35 f/2.8II from f/5 onwards. The 17-40 is a lens I've used with total confidence for demanding commercial work since they first came out in 2003. Read reviews...
Also if you have been following threads about wide zooms on CR you'll see the 17-40 has delivered largely positive experiences for those who own one.
Yep, indeed. Perhaps this guy haven't owned or shot with the 17-40. I am a happy owner of the 17-40mm and definitely I will still keep this lens!