Yeah, that's pretty cool. Personally having used the 1Dx III, I would spring for that. I have a 1Dx and it is fine body, but it is a far cry from the Mark-III. Night and day the difference. And they can be had for mid to low 3k range used, which is a great value today. And it still holds the distinction of having the fastest FPS mechanical shutter, if that matters to your style of shooting.

Messed around with the R3, didn't put it through it's paces properly. But the AF seems very nice.