I actually like the slightly older tone of Korra, mostly. The big issues I have with the series are:
Jumping to modernity the way they did made everything feel whitewashed, even though republic city has a strong SEA aesthetic.
Further extension of everyone sounding white (ATLA did this with its main characters which had some unfortunate implications)
I don't have a feel for the characters. By Book Two of ATLA I knew who Sokka, Katara, and Aang were. I only have that sense for Korra (and maybe Tenzin?).
THEY DID SUKI DIRTY
On the bright side, though, Lin Beifong is a fucking treasure.