I've only seen 1 episode so far, but IMO the format shift is worth it for the visual effects. Like, Sozin just straight up incinerating that guy would not have worked so well in the anime. And the actors seem quite good (the leads at least). My only real complaint is with the writing. And I mean, it's not as if the original didn't also have some pretty badly written lines in the first episodes. Adding in an actual 100 years earlier segment at the start is a big improvement, and it also gives us a taste of the kickass action scenes that are to come. At least for the intro to the show, live action seems significantly better than animated was.