Why does the rear of the nacelle have a "double decker" look to it?
And the fact that they wouldn't waste such a money shot on any other ship than the Enterprise.
That argument isn't useful for the "other ship", the one that's crashing down, which everyone ALSO says isn't the Enterprise. So I dunno now. I bet neither of them are the Enterprise.
Or else the Enterprise has been heavily refit/modified for this film.