The point is if the differences in size among the four different FF mirrorless formats appeared so far will mean or not any real advantage in practice.
So far no one can confirm or deny this, but so far some users seem strangely interested in spreading the doubt. This would be logical from a brand point of view (if I detect a flaw in my competition I have a chance to promote my sales), but a user with the same attitude sounds to me like the childish fanboyism of someone who needs the system he chose to prevail over the rest.
I would argue just the opposite.
Very basic physics tell us that a mount 10mm larger is bound to make it easier to design lenses with better corner performance. This isn’t something anybody has debated for years in the DSLRs world when comparing the F and EOS mount.
Attempts to deny this obvious fact can be interpreted as a fan boy attempt to minimize one factual advantage of another camera system than his own... sorry I mean of all the other camera system since Sony is the only one with a mount this small at this point.
The best evidence at this stage of this possible advantage lies in the specs of the lenses announced by the Canon/Nikon compared to Sony. I haven't seen any f1.2 lens proposed by Sony so far and the third party one are not that great in corners. We can debate about the usefulness of f1.2 lenses, but that's another story.
Don't get me wrong, I find the Sony system to be great and ton offer some unique values. I am just surprised at the epidermic reaction when a very reasonable fact is put forward that questions one aspect of its superiority. Fanboys rarely belongs to the side of common sense...
Cheers,
Bernard