Until then, comment likes "6D center AF point works better than 5D III in low light" is just an imagination.
Even though I'm rather critical with the 6d and Canon marketing, they do say that the 5d3 works up to -2lv, the 6d at half this light. I really doubt there is absolutely nothing to it, the question is if it's really a full stop, how slow the cameras are to af at min. light and how often these situations occur.I was reminded of an argument not a long time ago that some people can't accept that a lower-priced camera can have a better sensor than its significantly more expensive sibling (in the *same generation).
Nothing unusual about that, it's the complete package that counts, and of course Canon (and every other manufacturer) will take great care that more money means better overall performance. If you have special needs you can sidestep this system (like landscape with the 6d), but you cannot really escape the logic.
Last not least, if you don't want to read anything about 5d3 vs. 6d don't look at a "6D True High ISO King" thread :-p
I think you are oversimplifying things "you can sidestep this system (like landscape with the 6d), but you cannot really escape the logic". Is it logical to just take a camera based on your needs? Again, if you think 6D isn't the "best" for you then why choose it? You should have bought 5D3 where you are better served. You said "it's the complete package that counts". Now, that's not being logical. That's a statement that is too subjective. My point is, everybody has a need that is better served by something else as you yourself mentioned. Choosing a system based on your need, now that is what we can call logical. The point is, for those guys who doesn't need the best AF but needs the cleanest high ISO IQ, then 6D is really the King. Of course, it might be a different case for you so 6D might not be the King for you. Isn't that logical? Are we escaping the logic in any way?