Upload & Sell: On
This was was in interesting post by Beni
Chuck Westfall on the old Rob Galbraith forums once explained in depth why the 5Dc would lock on faster with center point than the 1DsII. Basically the 1 series used another layer of calculations to recheck focus that the 5D didn't hence the speed difference, especially in tricky lighting. The 5D was faster at claiming that it had achieved focus but whether it had or not was not confirmed until you got back to the computer. The 1 series was slightly slower due to making sure but when it told you that it was in focus, you could really rely on it, whatever the lighting.
The 5D3 I was checking was slower, annoyingly slower, but heck if it didn't nail that focus perfectly in low light with every shot at f1.6 on the 50mm. My 5Dc can't do that. 2 out of 4 if I'm lucky.