Korra is basically everything Aang wasn't: She's stubborn, hasty, inpatient and not as shy as Aang. Still, do not be fooled - Legend of Korra is an impressive animation work it goes flawlessly in graphic and motion design, it doesn't lack a humor nor a good, intriguing story.
Whilst that gives an edge to Korra, it also removes that childish and innocent humor enveloped in rather serious conflict.
Legend of Korra appeals to be way more mature than its prequel: The Last Airbender.