I know something about a fight between Peltz and Patel, but, it's been filmed at the other department (I thought it took place at the Spirit Oasis set). So I can't tell you anything about that, because I've heard some good stuff about that too.
I'm afraid that I can't tell you about the bending and martial arts too, because I'm just one of those guys filming it, so the editors and visual effects guys can finish it. I've heard some good stories about Industrial Light and Magic, so I think the bending will look incredible! The martial arts parts, are very grand and epic, as you might have read in the first part of the set report. In the background you see these warrios fighting everywhere. Every castmember who was part of a battle, was trained. Night had to interrupt the filming many times, because he thought that one single move in the background wasn't good enough, and then we had to reshoot the entire take.
Dev Patel also has some nice martial arts parts. Some parts with his sword (as the Blue Spirit, and as Zuko) and some parts with his bare hands. But compared to Ringer, he sucks. I've had the honor to film the parts where Zuko and Aang fight back to back at the Fire Nation prison/fortress.