I myself moved from the Terrible to the Just OK class after I returned my camera for an exchange. At this price range however, I wish there wasn't even a discussion about 5D3 low light AF performance except to question how it can be so good all the time for everyone without question.
So at the moment I am enjoying better low light AF with the 6D but I hope the 5D3 low light AF performance somehow magically improves after the next firmware update.
Are you talking about the AF flash assist issue or low light focusing in general? For me the two are very different. Thought the 5D3 was pretty hot in the available light focusing department, no?
Well, this has been discussed to death already and some see AF Flash Assist and Low Light focusing as separate issues. Personally, I see them as related and part of the same problem. Since every other camera I have ever owned performed better than the 5D3 in Low Light AF performance (in available low light, without AF Assist, FWIW), I expected at least somewhat better AF performance from the new $3K+ 5D3 in this category. Just call me Crazy! Alas, after exchanging the camera, I have been able to achieve similar AF low light performance to my older cameras but not much better. So, I got the 6D to compare and it works much better, like I expected the 5D3 to perform after hearing all the hype for many months. I've never used AF Assist and to be honest, I had forgotten all about it until I got a 5D3 and started reading up on why the low light AF sucked so much.
Thanks for clarifying that for me, albeit rather worrying clarity! I guess I’m really going to have to use both these cameras to make my decision. I’d much rather use the money for a lens rather than rent though. It’s the first time I’ve felt the need to do this and that in itself makes me feel that there is something wrong about buying anything right now other than glass.