Bob Howland said:
Pretty decent review, mostly because it agreed with my opinion.

... his videos have a very subjective, amateurish approach - see also his reviews of the Tamron 24-70. While this is fine if you want to p&s, it lacks tech knowledge (the fact alone that he expects 70mm to be the same on every lens).
In this case: The new Canon mk2 uses more doublecross af points on the 5d3/1dx, so it being as fast as the mk1 is a good sign since more precision usually means less speed. And a more detailed test might show that the mk2 has a higher af hit rate on Canon newest systems.