I liked the pro bending matches, but I thought the CG shots of the arena were pretty bad.
As for charming, I am not ready to judge that yet. Eventually, Aang's sidekicks became strong enough characters to have storylines of their own. Right now, Korra's fire ferret pals aren't capable of pulling off an episode about them. They're still satellites to Korra. I am not sure that Aang's sidekicks were that strong at first either, though they were the first characters you see in the original.
What I think the plot needs right now is more justification for a bender/non-bender divide. I understand that there should be some natural divide between the groups, but The Fire Ferrets are sponsored by a rich and powerful non-bender. We've seen in the first episode that the city is one of haves and have-nots, but not that the difference has anything to do with bending. If there's a problem with the arena and pro-bending is that it's kept the story trapped inside that world, where the greater conflict and the reasons for it never showed up.
