I don't like how they had to combine episodes. That being said, if they were forced to combine episodes, I don't think they cold have done a better job. The actors were all fine honestly, they really tried to stick to ethnic backgrounds portrayed in the show, and I have to imagine that limited their hiring pool a bit (there are no white, black, etc. people in avatar). THAT being said, why on earth did they pick the actresses they did for Azula and Mai? They look NOTHING like their respective characters. Not to mention where Azula's anger comes off as a sign of power in the cartoon, but I just want to smack this annoying child in the live action.
In general, it seemed kind of rushed, which I guess is "ok" since they only had 8 episodes to work with? (Idk if there were budget restrictions or whatnot) That being said (notice the theme of this review?), why add weird extra plot points into the story? Why add a character buildup to Azula? On top of that, why fill in lost time with ALOT of exposition dialogue? If you have to rush, then RUSH. Don't slow down for things that are so, critically, momentously, unimportant.
All and all, I don't know if I'd ever re-watch season 1. Will definitely watch season 2, for curiosity if nothing else.