I really liked the third episode. It was funny and it had some really good action scenes, and it showed how devious and kniving Amon really is; [SPOILER]which really shows when he takes away bending powers FOREVER with that chi blocking technique- scary!
It was on par with the pilot episodes, which was a big relief because you can usually tell how the rest of a series will be after the pilot, and i'm thinking it will really live up to the standards of the original Avatar. One thing i thought was really interesting was that the dialogue was very relaxed and didn't seem too forced, which surprised me considering how most dialogue in Nickelodeon action shows are.
one thing that worries me is that in the preview for the next episode [SPOILER]Korra is already challenging Amon to a one-on-one duel. Honestly, i feel like they're rushing Amon's dispatching too much. If he's being set up for the main antagonist of book one, they need to give him a long lifespan, but if he's already dueled with Korra, that loses some of his character.
overall, awesome. looking forward to episode 4