Mop was far better for most classes, wotlk just made it so we didnt have worthless specs, but mop is when most players, even ones who hated the way pandaland looked, liked the way the classes played.
Ele shams were great in Mop, terrible after that unless you played the frostquake ele spec in legion, then it was crap until they made the numbers bigger, so the class is technically very good but isnt fun to play.