Aside from making a clip episode, which was ****ing stupid, but understandable given the circumstances, I could not tell, no. And I have not noticed any drop in animation/sound quality. Maybe your internet is too slow.And you're not into the whole PTSD thing, or the dictator/world agression/Stalinesque thing, the human drama thing, or seeing Toph again, or possibly the funniest Varrick stuff the show has done yet. I'm not sure how someone can prefer Book 2 to Book 4, but I guess there had to be someone. Suit yourself.
Prince Wu sucks immensely; he's supposed to, but I wish he wasn't around at all. I'll give you that...unless you think he's the best part.
I'll concede that the comedy is there but there's nothing exciting. Nothing grabs me. The PTSD and dictator thing is cool but really, they haven't done much with it. I wished they had used that one episode to flesh things out more story but they couldn't cause of NICK and so we got a non-functional recap episode.
Book 4 had a lot to go on but it's almost done, 4 more episodes left and I feel dry. Hope it redeems itself.
When you compare this season against the rest; I was new to the whole avatar thing, so book 1 opened me up to this world and book 2 defined the avatar with Raava. But importantly, both book 1 & 2 had excellent foils to the protagonist. Book 3 was left open, cause really, what can the avatar not do? But it started strong and it became exciting cause people were out there trying to kill the avatar which opened up to nicely for book 4.