I've made a video where I compared AF speed of 2 bodies (7D and 6D) and 2 lenses (Canon 24-105L and Tamron 24-70 2.8 VC).
There are all kinds of combinations of bodies and lenses in the video.
Split screen in video, shutter press sync'd, beep enabled and panned left/right to judge which camera acquires focus first. Center and upper AF points tested, both from infinity and MFD.
More info in the intro of the video.
AF SPEED TEST