So after very careful consideration, I have to give this series only two out of five stars. The reason for that is rather simple:
I can appreciate the effort behind this series and quite frankly, I don't mind the shortened story. We have to consider that the aim for this series was to shorten the original massively - and they succeeded with that. I also do not mind the corners they had to cut in order to shorten the story so much.
But what I can't accept is the terrible acting, mainly from Aang. In the original, Aang was a highly confused and scared character with a pure and brave core that didn't know why HE is the one to carry all this weight around. He expressed real emotions and you could visibly see when he learned something new. In this series though, Aang appears to know everything and noching shocks or scares him. But the most painful things to watch were the scenes when he started a deep statement while an enemy was making a move. For example when Zhao is about to kill the moon spirit and Aang starts saying "You're right..." - these scenes feel sooo emotionless and terrible that I cringed while watching it. And this cringing feeling happend multiple times during this series.
I appreciate the look of everything - it's mostly really beautiful. And the bending is also not bad at all. But the landscape and bending are secondary factors. If the acting is not good, the whole series is not good.
Frankly, I don't understand the people who say that they love this series. Even though the story is mostly the same, it doesn't feel anything like the original.
The only thing this series did is make me watch the original again :D