I felt like it was a little... lacking, honestly. I'm not saying I wasn't satisfied for the most part. They wrapped up everything important about Korra pretty nicely, I think, and even a couple of subplots. However, anything they failed to really mention they can always cover in the future comic books they intend to make. I didn't really care that much about Iroh. Having Dante Basco come back to voice him was a mistake, and I felt like cringing every time Iroh II was on screen. I loved him as Zuko, but he wasn't right for Iroh. I was just fine with his split-second cameo where all they did was show his face as Kuvira and her gambit came into the city.
As for Kuvira, it was pretty obvious that they fully intended to imprison her for her crimes, and that's probably exactly what happened. Wouldn't it be hilarious if she got a cell right next to Zaheer and had to listen to him blather about his ideals when they so starkly oppose her own? I doubt they would do that, but I find the idea amusing.
It was also very clear to me that Suyin completely forgave Bataar, Jr. and that he would be welcomed back into the family. It was explicitly stated that he just needed to give the rest of his family time to warm back up to him and forgive him because he wasn't exactly innocent, but yeah. He's basically back with the family.
Katara, Toph, and Zuko weren't vital characters to the show. It was about Korra and the new Team Avatar. They made cameos, but they weren't necessary at the end because we already know what's going on with them. Toph went back to the Swamp. Katara stayed in the Southern Water Tribe. Zuko went back to the Fire Nation. It was pretty straight forward.
I'll admit I was surprised by the reveal with Asami and Korra. While everyone pretty much shipped them from Book One, I couldn't really see them being romantically linked until I saw their friendship start to build in Book Three. I actually really liked the idea of them together after that. Of everyone in the show, they have the single healthiest relationship. They may have had a rocky start, but they learned how to communicate with each other openly and honestly. They ended up being an amazing team, and I'm glad that they're implied to be more than friends now. I would have liked there to be a kiss at the end, but I'm guessing Nickelodeon wouldn't allow that because they're a-holes. I mean, they almost shut down an A:TLA sequel when Bryke told them the new Avatar would be female. I'm guessing they're the reason why we couldn't get an awesome kiss between two, consenting adults on the basis that they're the same sex. Even so, that look that passed between them as they entered the Spirit Portal was a really beautiful note to end on.
As for what I felt was actually lacking... The climax was pretty lackluster to me. I feel like the fight between Korra and Kuvira or really any of the fights that happened in the giant mecha were just... too soft, maybe. I never really got that seem intense feeling that I had during Aang's vs. Ozai, Toph/Sokka/Suki vs. the airships, or Katara/Zuko vs. Azula. Maybe there was just too much going on at once, or maybe they had too much to shove into the story before the wrap-up. I'm not sure. The fights just felt like they were over way too fast, and I never really got that feeling that would have put me at the edge of my seat. It also didn't affect me emotionally the way that even the other seasons of LoK did. I'm notoriously easy to make cry when I watch things, but the most that happened during this season was that I teared up a little at the end with Korrasami entering the Spirit Portal, but they didn't even end up being tears that fell. I don't know. Something was just... missing for me this time. Maybe it was the lack of character development in some of the key characters, maybe it was something else. I don't know.
I still love the show, and while it had great moments, I'm just not sure it ever really could have lived up to its predecessor.
