filmtwit
Desperate but not serious
I run a beat 20-35 f2.8L - it's pretty inexpensive these days if you look around and still a very good lens.
Before you spring for the 17-40 L think about finding a copy of the EF 20-35 f/2.8 L. Yes it's a little old, but it's a great performer. I've thought a few times about trying to trade it in for a newer 17-35 or 16-35 but it's hard to justify the cost when I can't really find anything wrong with it. And on a 5D it's truly a wide angle. Just a thought.
Chris