I have the 24-105 and had the chance to use a 17-40 while out in the Tetons for a day. Really liked it for the landscape stuff. I had been debating selling/trading the 24-105 for the 17-40 before leaving and decided to hold on to it. After using the 17-40, the debate is back on.
This focal length would really be used for landscapes, maybe the occasional daughter portrait and for walk around. I find that I grab the 70-200 for portraits inside or out, so the 24-105 really doesn't get used that much (except for when I go wider on FF).
Any of you used both and picked one over the other? Curious on opinions. Would also be used on a 50D on occasion but primarily on a 5d.