And by the end of the series, she becomes an excellent Avatar, exhibiting many of the same traits as Aang.
Counterpoint: While Korra did have her issues, she shows a lot more growth than Aang over the course of her series, but only because she has to.
Korra is brash at first (and already knows all but one element when we first meet her), but becomes humble later on, which makes her a very interesting Avatar, to say the very least.
She’s the polar opposite of Aang, who starts off very humble (that’s the airbender way) but eventually comes into his own once he masters all four elements.