The trick is the large number of genuine cross hairs - 41 of them. But the real boost is those new additional double cross hairs. These include the usual '+' type of cross hair, but now also include the 'x' cross as well.
This is what really makes the lock so strong. Double the ways of keeping the intended target locked while it is moving. Of course, i couldn't get any one to run around or weave like a footballer, but the speed at which the camera just locked on every thing was just astounding. I was using the 'right cluster' (that is the best way of describing it) as i panned round the hall. Had about 20 focus points in it. The focus points lit up and went out light christmas tree lights and beeped merrily away - hence my statement that 'if their had been music they may have beeped to a rhythm'
But the strangest thing was - they didn't seem to get in the way of the seeing the subject. That was really strange, so much more unobtrusive than the 1D3 AF system.
Must remind you that with AI Servo, the trick is to lock on to the right subject in the first place, but once locked...