In my opinion, Thrice Upon A Time is probably the best Eva piece of content in the entire series, although it's definitely best watched after the other movies and anime before it. It suffers from the usual "a wikipedia's worth of lore is going over my head" problems of other entries in the series, but that doesn't detract from the experience too much. They say the best way to introduce lore is by hinting & implying it, and this does do that; you can get all the necessary stuff through context clues, in my opinion.

There's spectacular animation and music as usual. The 2D animation holds up to today's expected levels of beauty. A fair bit of it is CGI, but it's the good kind. In terms of how well it blends into the 2D animation-- it doesn't, but it's obvious a high amount of technical work and thought has been put into the scenes, and this definitely contributes to the satisfaction in watching them. Unit 08's acrobatic fight in Paris still stands out to me in my memory. Although, it looks like right at the end with Gendo & Shinji's duel the complexity of animation took a bit of a hit, and motion capture was just used. And at times the enemy Evas looked a bit sloppily kit bashed.

As for the writing, I think the word "closure" fits the general direction/goal it was moving towards. And it nearly perfectly accomplishes this in my opinion. Everybody gets one final spurt of character development in order to get them out of the atmosphere of despair of the past entries. Not 3.0 and the other remakes, Thrice Upon A Time has more hopeful tone than even the original anime and tries to give all our favorite characters the happy end we've been wishing them for so long.

Shinji has finally grown into a respectable character. When it comes to Shinji, I think people are generally split between being angry at his mental feebleness, and feeling bad for & resonating with his inner suffering. Feeling both is a part of the identity of Evangelion itself, so it's been a pleasant surprise to see Shinji grow so much from being a naive child. He's gained the strength to bear the burden of grief and tragedy, overcoming the loss of New Ayanami, and see the part his weakness & cowardice has played in past events.

And in Shinji's final battle with Gendo, he gains the maturity to resolve things with his father. The battle could've been a flashy fist fight, and in karmic fashion, probably ending with Ikari Gendo miscalculating something in his plan and not being able to see his wife again while being consumed by a "true hidden last boss" like the End of Evangelion.

"Resolve your conflicts by talking it out" is a pretty cliche trope that is equally unentertaining to watch if not done right, but Thrice Upon A Time has managed to do it right. By placing Ikari/Ayanami Yui hidden within Shinji, the main obstacle between father-and-son bonding has been made into a tangible obstacle for Gendo. It's a novel way to overcome Gendo's stubbornness and unwillingness to talk.

At the end of the family confrontation, we go character by character and make sure everyone gets their happy ending.

Asuka has finally learned to live with the vulnerability of needing companionship, as well as made up with Shinji and confessed the feelings she had from 2.0. Touji has finally gotten together with Hikari, and Kensuke has found a meaningful way to use his survival skills (although these were shown in earlier scenes). Kaworu and our original Ayanami haven't been forgotten either, and are given peaceful lives. Shinji even gets to actually meet his mother.

All in all, this was a great movie to end the series with. My only wish is that an Epilogue was added in. This also applies to the endings of other Eva series entries. I think me and everyone else wouldn't complain if we got to see just a snippet of everyone's lives after the end. I think there was also the implication that everyone had gone to live in different universes, so it'd be an opportunity to learn about more lore.