I also tested 2 copies of the Mark II, as well as comparing to my Mark I, and did these same tests at 50 and 70 mm on all 4 of my bodies (7d, 5dM3, 1DIV and 1D-X). My results were very similar in that 1 copy of the Mark II consistently had considerable dropoff during the AP sharpness from 2.8 to 4.5 on every body!! I repeated these test several times, and at different focal lengths, and concluded that that copy of the Mark II had issues and returned it. On the good copy, sharpness from 2.8 to 8 was maintained at a high level, thus reassuring me that stopping down on this lens adds no 'real life' improvement in sharpness/quality.
I also found the same improvements/consistency in the Mark II AF 'consistency' over my Mark I.
Sure glad this more comprehensive analysis confirmed mine.
I could not be more pleased with the improvements in Mark II performance, so for those wondering if it is 'worth it' (over the Mark I), I would say emphatically yes.