His EXIF info says 5D.
I just used the 17-40mm f/4 for the first time on a "serious" assignment at a weekly exotic round-up. The Lamborghini dealership here brought over 3 new models to show to us, and this was one of them!
I honestly don't think this lens is very sharp, specifically near/at the corners, but then again most UWA lenses are not.