Here's some shots of rare Swedish Red Ear'd
Biggies Piggies taken with the centre point of a 6D with a 50mm f1.4 @1.4. Nails the focus plane near as damn it 8 times out of ten. Cropped and recomposed, so not 'focus and recompose'. Biggies Piggies just won't keep still for a moment !
We have an almost 2-year-old toddler who can move about as quickly and randomly as these piggies, and the AF with my 6D and 50 f/1.4 and 85 1.8 does just fine under f/2.0 using the center point. Overall, my hit rate for moving kid shots is in the 75-80% range, and I'm happy with that. I know a 5D3 or 1Dx would do much better, but for my overall use (kids/landscapes/portraits/macro and a little high school golf and cross country) the 6D is a great camera.
Exactly. Four years, many people (myself included) were clamoring for a camera that unified the image quality of the 5DII with the autofocus of the 7D. Canon delivered, even better than expected, with the 5DIII – and charged a premium for it. But they also delivered the 6D, basically a very modest update to the 5DII (already an excellent camera, AF notwithstanding) with a functionally equivalent AF system, but at a lower price. That's a win-win.
Well summarized, I agree. If you want a camera with superior AF, buy a 1Dx or 5D3. The 6D has IQ in the same ballpark as the higher end cameras, but a limited AF system. That's why its $1K+ cheaper than the 5D3. Personally, I'm glad Canon gives us price and capability options.