Saw it the other day. Much better then expected.
I'd go as far as to call it a potential masterpiece of character building. It's the little things, like how Arthur Fleck slouches in his day to day, and when he starts to snap he's dancing.
I'll let a friend from my Facebook ring do the talking:
And yeah, the mental health message was really strong, such as the way people insist the mentally impaired act like they aren't. Or how when government cuts happen, it often hits social services, leaving the needy no where to turn.