That stinks. I've had excellent luck with my 5D3, and I shoot tons of action stuff. It's almost magical on focus, similar to the reports I've heard about the 1DX.
yeah, not sure. In those cases maybe was user error as I said. But I'm quite positive I'm doing things right on the Mark II. If I can make it home before it's dark, I'll do more tests and see how it goes.