Great shots.
As for the 6D's AF, I've been involved in a couple of those "6D AF sucks" type threads in the past, where the lynch crowd became a lot quieter after I showed them my sequence of off-center point tracking shots from my 120-300 2.8 OS at 300mm and 2.8; and that's a Sigma lens, not even a Canon... Runners in the park, cars in motion, and birds in flight. All shot with the top AF point. I mean, it's sad that I had to go to the park and actually get real world shots to prove that yes, it's possible.
What's even sadder is that for most of those shots I could have (should have) really been using center point.
Yup, the 5D3 is better at that, and probably so are my 7D and 70D bodies too. But to say that it's impossible is just ignorance. And when shots like yours surface, it's never good enough, there is always something to criticize (just like Bakewell mentioned) The usual 5D3 argument is something like this: "but can you show me crisp 100% crops of your kids in action where the off center point was placed on the right eye at f/1.2??"
Now back to topic. Great shots, looking forward to more.