My hypothesis is: the artists screwed up and didn't communicate with the set-designers. The scale varies from shot to shot, ergo scale measurements are useless (although I find it funny that the only scene in which the E is conclusively smaller -- the shipyards -- is summarily rejected by the Big-E booster crowd). The only constant is therefore the exterior appearance, which matches up almost precisely with the TMP refit: the windows, the hatches, the photon torpedo tubes, etc... My conclusion is therefore the original intent was for the ship to be basically the same as the old, but on set JJ wanted BIG -- and no one realized that BIG meant the ship design was insufficient. Anyway, I've wasted about enough time arguing the "correct" size of a pretend ship. I will now go apply the "scientific method" at the pub. My hypothesis is: I will get sloshed if I drink beer.