Hi Dean,
I think you'll like it. Make sure you read this http://www.learn.usa.canon.com/resources/articles/2012/1dx_guidebook.shtml
And dont forget to figure out the best AF micro-adjust setting for each lens you use. I use the Lens Align Mark Ii and FocusTune software combination for this (with the new 4rd gen ruler and large target) but there are other tools for doing this.
Thanks Ellis,
That's the AF manual I referred to by the wrong name earlier. I read it before the camera was delivered and had it handy while familiarizing myself with it. If not for the guide you referred to I'd still be trying to figure out how the AF works. Some of the setup parameter detail names are a little counter intuitive, and if you don't shoot sports the "Case" icons don't help much either. The guide really clears up everything.
I spent some time today with micro-adjustments and got a reasonable sunburn doing it. For long lenses I have to go to a local park to find a place large enough (200 feet for 1200 mm) and flat enough without obstructions. A laptop and FocusTune could work in that setting and would probably be easier, but I used a method I found not long ago called "dot tune"
http://www.youtube.com/watch?v=7zE50jCUPhM. I was skeptical, but my results were repeatable on the same camera within about two AF adjustment points, and results for one camera plus an offset line up reasonably well with separate results on a second camera with the same lenses. Shots carefully focused in Live View also match AF based shots after micro-adjustment, so I'm pretty confident in the settings. The method involves precise focusing in Live View, disabling AF, and then finding the spot in each direction (+ and -) where the focus confirmation light no longer confirms focus. The micro-adjustment setting is the center of that range.