Some beautiful light you've got yourself there mate. Wonderfully executed shot! I'm probably getting the 17-40L once I go full frame soon hopefully. How do you like it as a wide angle lens? I am considering the 16-35L but don't know if it's worth the extra bucks.
I had both, and honestly for landscape I do not see the difference. With 17-40 it is always up to which production sample you will get. Some are pretty bad, and some are good. Canon doesnt have a great wide angle zoom lens. But neither do the other guys anyway Just my personal thought.