Like Kel, I got burnt out on the mastery grind after a couple weeks. The new zone event design is a great start in a new direction, but success is still entirely dependant on getting lucky and dropped into a map full of players who are actually working towards the objective. Made worse by the fact that it all runs on timers, meaning that unless you get in exactly on time your out of luck and will be faced with an unwinnable map instance (I'm looking at you, Dragon's Stand!).
I have had no luck getting into a raid pug, despite being a druid.