Overall, I would say it was good. Some performances were A1! Aang and Gyatso's scenes made me cry quite a few times!
I very much dislike Azula's actress. She looks and acts like a 5 year old girl. Not the cold and calculating Azula that we all know.
I didn't like Zuko's actor either, but throughout the episodes, he grew on me. A bit sassy but I liked it lol.
Also, throwing multiple seasons into one was crazy. They did too much with that one, so it was a bit harder to follow along.