In Grizzleheim, I applauded KI for making a world more about the story than the rewards (this was before the Morganthe line).
Then Wintertusk came out. I was excited because I'd just finished GH and was exactly level 50. I was expecting a simple story continuation, and while the storyline WAS good, I noticed that the average quest gave around 5000 XP.
I was severely OP in Celestia because I was already level 56 when I went in.