AI servo
A lot of people, myself included are quite annoyed at the black AF points when using AI servo mode on the 5D Mark III. It's nearly impossible to see in some situations, especially in low light. I think most people would like the ability to turn on the red AF point you see when you lock focus in one shot mode. I'm not sure if this was by design, or if it's actually something that was overlooked in testing.
You can see the discussions at [FM] and [POTN]
I will say that the AF works terrific in AI servo mode, it's just tough to see the AF point at times.
Firmware fix?
I am told by a couple of people that the above issue is known by Canon and they will fix it with a firmware update in the future. The fix may take some time though.
Here's hoping they also add the ability to change the image review zoom button mapping back to the top right.
You can let Canon know you'd like it fixed here.
Planet5D with Chuck Westfall
Chuck Westfall actually talked to Mitch at Planet5D about the two issues above. If I read anything into it, it seems the red AF point illumination is a priority and remapping the zoom button less so.
The issues come up at about the 8:00 minute mark, but the rest of the interview is worth watching too.
From: [P5D]
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