I guess I'm missing what the big controversy is over the size. If the two 1701's dont' co-exist in the same universe/reality as each other, what difference does it make? Why is 700+ meters any less valid than 300 meters?
I've seen people in other forums say "If it was only twice as big, I wouldn't have a problem, but this is stupid". Why? Seems to me if it were 350 meters that would be as inexplicable as 900 meters. Is it because it's bigger than the Galaxy class, and that's offensive?
One of the funnier things I've read is people saying, "Ridiculous. If it's that big there's no way you could get it from the ground into orbit." Because, after all, we know how much easier it is to get 190,000 metric tons into space as opposed to 495000 metric tons.
EDIT - Just got a reply from Bob Orci over at TrekMovie.com. He tells me that the so-called "Supreme Court" at Bad Robot will be releasing an official statement on the specs of the Enterprise and the Kelvin "soon". They're doing a Q&A there, I asked about the Enterprise and the Kelvin, so hopefully next week we'll know (for better or for worse).