I just hit 84 last night and tried to go back to the Stonecore to try the last boss again (who i havent been able to beat yet) before bed... I was able to smoke this dungeon (up until the last boss) at 83, and am unable to clear the 2nd boss at 84... i just run out of mana. Its very annoying. I know I need some more gear upgrades, its just very disconcerting to level up and go backwards in power though.
I know itll be fine when i get some better gear... just complaining... blah.
Very interested in seeing how my disc priest healer is going to feel at 85.