The animation quality isn't that bed really. The frame-rate is a bit slower than other Japanese animated films, but the point is more of the use of them over the fluidity itself.Check out this clip from 2.22's phone conversation with Asuka and Misato
, for example. Starting at 41 seconds into the clip Anno starts using a very specific aspect of the French New Wave cinematic technique that he wasn't able to pull of in the TV series because of the limited character animation through the show, where it looks like the Asuka's dialogue was covered in one long take, then that take was edited down to specific segments that the filmmaker thought worked best for the scene. Even though other aspects of French New Wave appeared in NGE, Anno was never able to utilize this particular part of it because the limited animation kept the characters from having the proper blocking necessary to make the cuts as apparent as they needed to be. Because of this lack in character blocking through animation, Anno would instead create scenes that would use the unedited long take
in the original NGE TV series, merely "skipping" the step where he as a filmmaker would edit the take down into shorter segments.
It's because of this use of French New Wave editing techniques that was finally made possible by the better animation fluidity when compared to the original TV series that makes it a much anticipated improvement to the Eva franchise. I mean, sure, you can argue that Summer Wars
had more fluid animation (which it did), but the filmmakers never bothered to use their fluidity as creatively as Anno did in his NME series. It's like Mamoru Hosoda simply shrugged as said "Well, it's smooth looking, and that's all that matters to me."
(I say this as a great fan of his two latest animated films, and an admirer of the visual aesthetic brought to Yoshiyuki Sadamoto's character designs in his movies.)
Also, I wonder if one can argue that the character animation is NGE wasn't as impressive as the character animation from other Japanese animations contemporary to its time. I seem to remember thinking that the character animation in Nadia: The Secret of Blue Water
(predating NGE by about 5 years) was much better than the character animation in NGE. Maybe we just need to realize that it's an Eva series, and just like the TV series predating these new films, Evangelion battle animations take priority over the character animations.