Some more messing around with 5D3/5D2/7D and 24 1.4 II. The 5D3 definitely handles it the best. Sometimes the others do well with it, but not always. The 5D3 AF has some magic that makes it get a very, very high percentage in focus at all sorts of subject distances and lighting conditions, only under super poor (as in a single 40 watt bulb that is half obscured and shooting tricky targets not being directly lit by even that) lighting does it start to miss semi-often but even then it does the same as 5D2 and much better than the 7D (or 50D for that matter). For some tricky and not so tricky targets at a wide range of distances the other evening the 5D3 barely had a miss and by far more than half were utterly dead on at f/1.4 (the rest were in focus but just barely a smidge off of perfection, but totally fine) while the 5D2 and 7D were having plenty of clear misses and many fewer absolutely utterly dead on hits.
And paired with the high precision AF of the 70-300L, as per lens rentals, it really does tend to just nail the AF spot on with that one, absolute perfection.
Job well done.