TLDR; Better than the stupid movie, but still far beyond the legend TV show.
I watch only 1.5 episodes, I kinda already hate it, sorry, but here's my review on those episode 1, and 2 (half).
The good things are effect or CGI, and I guess that's it.
The bad things are writing, acting, a bit of personality change, honor -> glory change.
Writing in this series are a bit too dramatic I guess. I hate that the reason Aang got stuck in the storm was because of a night stroll to calm himself, in the TV show, he's so damn scared, he ran away, not just strolling.
Acting feels stiff. Doesn't feel natural at all. Especially on the young actors and actresses, I feel like they kinda wait others to finish their sentences, than they can speak.
Personality changes, early Aang doesn't seem to be too childish in this Netflix show. In the TV show, he is really childish, only wants to have fun and feels relatable. Iroh not so good humor. Sokka being not misogynist. Katara not sassy.
Honor changed to Glory for the fire nation. Zuko's main arc is to redeem his own honor, not bring glory to the fire nation. In this first 1.5 episode, I didn't hear any "honor" being spoken, what I got from the TV show, is that Zuko's redemption is revolved around "honor to humility" change.
I don't know though about the next episodes. But so far, I don't like the show.