It isn't exactly the story i expected, but i really liked it! (I will say i really loved the original ATLA series, but have not catched up with any other material from the world outside of the show.)
The story was very well written, and it added a lot of interesting stuff to the history of the Avatar world! The pacing was phenomenal! I was a bit afraid of it in the beginning, because i really wanted to like it, but once the plot starts, it really starts!
The story feels very ATLA, although it has a much more mature tone - it gets much darker at points, and there are plenty of sudden, harsh deaths. Certain plot points were almost taken from ATLA, but i didn't mind their recycling - they are good plot points (found family,

death of the mentor

).
Of course, i have to mention the (very clear) LGBTQ representation in the story! :D