I am very wary of watching it, and a lot of my worry centers on Katara. "Softened" doesn't sound great - though you said she does get to be angry? That's the thing I really expect to be mishandled, the way Original Katara is angry AND idealistic AND supportive AND stubborn, a whole complicated mix of a person. (And it's not like the original creators didn't completely screw her over in Korra, so apparently they didn't get her or value her complexity either. Must have been some kind of alchemy in the writers' room of AtlA...)

Honestly I think the Katara/Aang in the original was 95% one-sided and would happily bid it farewell in an adaptation. Either give Katara's feelings some time and space (like they very much didn't between Ember Island Players and the finale kiss) or just let it be a close friendship. (I don't object to the idea that they eventually marry; it's not about shipping it or not shipping it for me. I just really hate Katara being reduced to Aang's Hero Prize when literally one episode before the finale, her reaction to Aang's romantic fantasies was "WTF?! There's a war on!" and almost every "romantic" moment between them was about Aang's crush.)

Losing Iroh's layers feels like a very bad writing choice. Is it just that no one has layers anymore? Weird to think that the kids' version is the one with the complex characterization.

I don't know... I probably can't approach it with an open mind to the story they want to tell, so I probably shouldn't approach it at all. :/