Not necessarily directed at you but I'd like to point out that most people, even among the people who hate or dislike how he looks, thought that Leto would be pretty good to great in the role. I think that gets ignored by people who have been staunchly defending the look from Day 1. Very few people ever questioned Leto or his ability to play the character.
I expected Leto to do very well in the role since he was cast, but I still don't like the character design/costume. I highly doubt I ever will.
But based on the small snippet in the trailer, it seems he'll have the best Joker voice of the three movie adaptations, IMO. I think it's really good. Really I think performance wise he'll be up there with Heath Ledger in terms of straight acting performance. I think the thing that will always set Ledger apart though is the writing, I'm literally just guessing but I don't expect they will top the writing for The Joker in the Dark Knight. I think that's another thing that gets kind of lost in the fray, as good as Heath was, it was the writing that was really the best thing about Ledgers Joker IMO.
But yeah, definitely looking forward to Leto's performance, even more after seeing the trailer.