One thing that bugs me about Monk is the lack of weapons in their attacks. No matter what you equip, it's the same unarmed punch and kicks. Cool for Martial Arts theme, but when I'm fighting a big bad I want to be armed with the sweet new drop that I got. I'd be much happier seeing animations that use my weapons. That's a huge part of the fantasy of what character I play, I want to see my character's progress visually.
It's not make-or-break the way patch balance would affect the class, but as an MMO that's focused on customizing your character, these things are important to me. It's different than a caster not using their weapons, since their fantasy is about casting spells, whereas a Monk is still a melee character and should be using their weapons to fight, like Chen using his staff in the opening cinematic.