Probably my favorite FE game I've played so far.
Ike's a really good character. The nature of FE makes it so that it's pretty hard to have good supporting characters beyond just their vibes, but I do like this game's cast for what it's worth.
I liked the plot a lot less after Begnion. The magic medallion stuff didn't really interest me at all compared to the compelling themes about uniting different cultures and ending discrimination.
One thing that somewhat bothers me is how characters would be joining your army super late into the game. I get that people die but towards the end things start feeling really bloated and my army was filled more and more with characters that I barely even knew. Also, limiting supports is dumb. Even if you don't want to give out the mechanical benefit too often you still shouldn't put a hard limit on them given that a good amount of them have character backstories, and for some characters the support scenes make up a majority of their lines. The dialogue in general is really well written though.

Very ambitious game, I'll give it that much. I like the rotating armies idea both narratively (mostly) and in game play, and I think the amount of challenge this game offers is also mostly enjoyable, but it is pretty aggravating for some missions, especially the long ones if you lose a main character.
Writing-wise, I feel like we're always just a little bit short of being good. There are some fun ideas in just about every arc, but I never really feel like enough is done with them. It doesn't help that the rotating PoVs does make it difficult to really develop characters or plot points.
The most glaring issue with this game is the complete removal of the support system, and it's the primary reason why I'm dropping it. Supports are the main way to have any character writing whatsoever, and removing them entirely makes many units (especially new ones) feel like piles of stats more than people. I think it also throws off the pacing, not having any non-plot scenes between chapters.
Overall I think the game is fine but it's not good enough for me to really want to play it more than something else.

I respect what this game is trying to do with the multiple endings, but god damn, it does not make it any more fun to spend maybe a third of your overall playtime on repeated content with little change in gameplay. (This is speculative, I only got to Route B before deciding I wasn't built for this.)
I like everything else. Every character in the cast is great. Weiss in particular is my favorite but they all bounce super well off of each other, both for comedic and serious moments. I can tell that Yoko Taro is cooking some insane shit with the plot, good enough for me to at least want to watch the rest online (a rarity when I drop games, tbh)

EDIT: Okay, I watched the extra content online. I don't feel anything about this at all, and for something that's supposed to require so much time investment to get to, that's not acceptable to me. If I wanted to experience sadness from wasting a bunch of my time, I don't need to play a video game.