Legend of Korra did have a much different animation style then The Last Airbender. That took it into a different level, making it way better than the first by miles. I enjoyed LoK a lot.
If anything, I think it was kind of rushed when Korra
can just suddenly enter into her spiritual links of the past Avatar so sudden, when she couldn't do jack shit about the spiritual world at all.
The ending was really good, but the aforementioned topic still bothers me and stopped it from being a great ending.