No Real spoilers here. Emotionally, you might feel as though your soul has been sucked into a black hole by the time the movie is over. It is well written. The Cinematography is outstanding. Acting was superb. The challenge is, you can't unfeel or unsee the movie.
I thought it was excellent and agree with most of your assessment @Rev579. I don't agree with the violence but the social commentary of handling mental illness and social outcasts was likely on point. I think we do a pretty poor job as a society (here in the states anyway, not sure how other societies work) handling the mentally ill. I really like how they developed the backstory of The Joker similar to how they did with Batman in The Dark Knight. When they finally decide to make the showdown I think they have a chance to maybe make the perfect super hero movie. So much pain. So much tragedy. So much opportunity for heroism. It could be epic. It's all just real enough to maybe be possible. Just "real" people responding like normal humans. Not mutations or super powers, just gadgetry and illness. I'm a huge Marvel fan so it pains me to have enjoyed the DC universe piece to this level.
I don't even remember how I felt about it after watching it. It couldn't have been too bad or I would have got up and went to do the dishes or something.
The only good joker was in batman movie mad back in 1989 jack neilson was the best joker ever but that's just me