Canon 1dxmark ii or R6 for sports?

The 20fps on the R series is great, if you want to eat up a card.

Never use anything for sports only single point AF so the issue of eye/face/head tracking is largely irrelevant. Mkii is a tank and built for sports R6 is a capable performer, but I wouldn't want to risk it in all weathers. I would also be wary of the EVF v OVF as I know a few sports freelancers who have tried the R6 for soccer and they've lost shots because of the slight lag between the action happening and you actually seeing it.

There should be no issues with lag on the R6. If someone is missing shots, it isn’t because of the very tiny lag. Also if they knew what they were doing with the camera, they would have gone to ES and used 20fps where there is no lag. Sounds like more that somebody tried a R model during a game using old school methods and never figured out all the settings and new ways to shoot to me...

Secondly, the tear down of the new R bodies showed they are very sealed, in fact so much that the new seals are contributing to the fact that they get warm very quickly and don’t cool off that fast.

Finally there are ways to mitigate getting water on your gear if that is a concern. Many products and DIY ways to prevent that. If one would be that concerned with the R series, they would also be concerned with the 1d series.

Is the R5/6 a replacement for the 1d? No of course not. Is it maybe 80-90% capable? Yes. Is it going to be better in some situations than the 1d series? Yes of course.

I had always used center point or center point expanded for sports on the 7DII but the face/eye tracking of the R6 is so much better than center point, especially in how you can just lock on and then recompose the shot as you want