Aside from the balance concerns and end-of-expac-blues that exist in every expansion, I would say MoP was decent. The only real negative for me was that the art style felt very same-y to me within the expansion. Even ToT, which was the Troll raid, still felt like a Panda raid. All the zones featured green as one of its primary colors. Raids were overall well designed, but only a couple fights really stood out (Lei Shen, Seigecrafter Blackfuse).