Awesome wide zoom
I love this lens and have really nothing bad at all to say. I've owned most of the Canon wide zooms over time (aside from the first generation 16-35 f2.8L that this replaces) and this is by far the best. I find it to be very sharp and the flare to be extremely well controlled for a wide zoom. I shoot it straight into the sun on many occasions and while a good prime might beat it, it is outstanding for a zoom. The 82mm filter size might be seen as a negative if you own 77mm filters already. This large a polarizer is not cheap! Handling and feel excellent. Weather sealing has never let me down. It's a weighty piece but worth it given the build quality and the f2.8 speed. Distortion seems minimal and do use it for architectural work on occasion, but my primary use of the lens is for sports and landscape. I would recommend this lens to any serious Canon user and I would buy it again without doubt.