Excellent post Busted Knuckles!

I would add, that this is a relevant place for the 1Dx III to shine.

Think about it, you get 20fps mechanical vs 12. Now is that unusable? No. But having used the 1Dx III. It is a substantial difference and I would dare say a bigger improvement compared to even 20 vs 30fps.

12 fps is over 50% slower than 20. But 20 fps is only 33% slower than 30.

So it does boil down to your needs. But I will say, with all the improvements of the R3, it's gonna be really hard for anyone to make that trade off if they are a working pro and deal with fast action all the time.

In my case, I think a good used 1Dx III might be a better value for my use since I don't want to switch over to RF mount just yet. I'm pretty happy with most of the EF glass. And I can pick up a 1Dx III body for a significant discount used. I have been seeing them lately on local classifieds for $4500. VS $6000 + tax. And many times I'm getting extra batteries and memory cards on top. Which are just a bonus.