From what I’ve heard they removed important character traits from each protagonist. They took away Aang’s playfulness, Katara’s maturity and sense of responsibility, and Sokka’s growth arc.
Or for a quicker summary: they combined the Jet episode with the machinist and the secret tunnel.
They also seem to have removed all meaningful interaction between aang and katara in favor of exposition.
What kind of interactions are are going to be interesting between characters whose important traits have been removed?