shorter range. heavier. more expensive. bulbous front element. much prefer the 16-35L II.
But then again, you always prefer Canon gear in every single discussion. And that doesn't change the fact that the 16-35 II is an optical joke compared to the Nikon 14-24.
On topic. Yes, a sharp UWA-zoom from Canon is still missing. It doesn't necessarily have to be 14-24. A razor sharp 16-35L III or a 16-50L would also be ace!