Hope this one becomes a reality. If IQ is similar to the Nikon version, I'll drop my 16-35mm f/2.8L II like a hot potato.
I wouldn't, but your style and needs as well as budget, I know, are quite different than mine and still, I am very happy to see this lens releasing for Canon systems. I wonder if this will best, the 14mm Canon prime (I hear that currently, maybe someone can confirm, Canon's 14L prime is superior to the 14mm end of Nikon's 14-24 as well as superior to Nikon's 14mm primes???)
I think if I was willing to chop off the 35 mm end of the zoom, with an intention to pair it to a 24-70, that I would just go for a 14mm prime instead and save a little size and weight. I also don't like that the 14mm prime and the 14-24 lenses have unprotectable, aspherical front elements and I'm not at all convinced that leaving the house with just a 14-24 would be anywhere near as useful for many forms of photography as the same scenario with a 16-35. The 35mm end of the 16-35 is what lets the lens go from ultra wide angle, to a normal viewing angle. You can stick the 35mm end in someones face and get an intimate portrait that doesn't make them look like a mutant, not so with the 24.