Another great thing about The Legend of Korra is the setting. Republic City is set in an industrial revelation type economy. The city uses bending as a source of income with the pro bending matches. It is a great addition because these fights are very well animated and a blast to watch. We have cars that looked like they were modeled after the Model T, big skyscraper type buildings, and steel everywhere. There is also the overwhelming presence of people in the city. One thing that the first Avatar show lacked was the feeling that Aang and his friends were a part of a big and living world. Every scene that takes place in Republic City has many people in the background that really make you feel like the characters are part of the city. With so many people comes the conflict of the story; a group called the Equalist want to end bending because benders "apparently" suppress the non benders. The leader of this group Amon is a really well written villain because you actually feel for the guy. He has a realistic goal that makes this show more about one person's view vs. another and not the typical "Good vs. Evil" that is overused.
This show is the rare case where I think this sequel surpassed everything the original had to offer. If you haven't seen the first Avatar or this one, I STRONGLY encourage you sit down and re-watch them. You can at this present time watch every episode of the original Avatar on Nickelodeon's website.