Got mine today!
And even though I haven't even done any afma yet, except a ballpark of +5 at 70mm, this lens changes everything. Holy mother!
I haven't seen sharpness, color and contrast AND blistering AF like this since I owned the 300 f2.8 IS. Simply mindblowing. And to say it's as sharp as the 24 L II is a big understatement for the three copies I have owned of that lens, it's WAY better. Superb build. Weight and balance on the 1d X is perfect, a bit tight zoom-ring, but that's just because it's spanking new I guess.
And I got a great deal with special offer and cashback so price isn't a negative anymore. I might miss the deep hood of the mk1 which was great for keep rain off the front element, but hey.
Oh, and it came with the pinch-cap, which I still frikkin hate, I'm buying and old one for it.