The only gripe I have, other than the "and now everything is okay again" ending, is that the Equalist plotline doesn't seem resolved. Hopefully this picks up, because the writers were dropping a whole bunch of "Amon may be a monster, but the people still want equality" points throughout the series. Hell, I thought the series was going to go a different direction when that one woman yelled out "You're our avatar, too" a few episodes back. I just don't feel like the Equalist's points were addressed, just dismissed as coming from a madman. It's guilt by association, and I'd be surprised if the second season has everyone living peacefully together just because.
In all, though, it was a good season. It's biggest weakness is in the brevity of it. Maybe a few more episodes or stretching the Equalist plot out over the two seasons would have given every character a chance to breath and have an arc, and allowed them to flesh out the depths of the Equalist plot. And maybe give Bolin more props, since he got snubbed from being Korra's main beau. Bolin4life.