What about 5D4? I'd much sooner pick one of those up after some of the stories on the 100-400ii thread about mushy images from the 7D2. And I do love FF.
And regardless, still am not likely to, as the 5D3 does well for everything else I shoot and these ones are still much better than the iPhone pics that the foster dogs get otherwise for their adoption campaigns.
No idea about the 5D4. I think it is ridiculously expensive and none of the new functionalities appeal to me, I do not need them so it is not worth the price for me. My guess is that it is not too much better in this area. Fast moving dogs require cameras designed for sports photography, 7D2, 1Dx, 1Dx2. I would rather pick up a 1Dx than a 5D4.