To those uncertain about The Legend of Korra: watch it. It is every bit as good as the original Avatar series was. Set in a more modern world, the new avatar is faced with struggles of a different kind, struggles that relate more to our modern world. Technology is booming, crime is rising, and a revolution is awakening. This is much more real than the last series was.
The characters are built incredibly realistic, too. Korra is a revolutionary heroine: she is realistic, imperfect, hasty, rebellious... all the things that a teenager girl really would be. Faced with difficult decisions, she doesn't always choose the right ones, yet she always learns from them. The other characters also show these strenghts and weaknesses along with equal depth to the characters of The Last Airbender.
While different, troubled, and darker than the original, everyone should give The Legend of Korra a chance. It has many wonders to be seen as of yet and her story is only just beginning.