The zones don't feel much immersing. It's all a bit wonky imo. The only bosses I have enjoyed are Elegon and Grand Empress Shek'zeer to some extent. The voice acting is bland and many bosses feel like they are just there so they could tell us that we got so many bosses in MoP. Tier 11 was way better, had much better additions when it came to heroic modes compared to normals, the voice acting was awesome and the fact that you had actual story villains in the raids made it so much more engaging to fight the bosses preluding to them.
My 2 cents.