Just saw this yesterday afternoon, and I think it's fair to say that as I whole I genuinely hated the movie. The entire outing felt disjointed, shallowly motivated, and lacking in actual fun and excitement. Everything felt like it happened just to happen, with no momentum behind the actions of any of the players. Harley's Joker sub plot had no suspense to it because Deadshot already knew, and Rick Flagg was a cardboard cut out of a generic "SOLDIER MAN". You're never worried about her getting caught sneaking around, which moments like her taking the elevator without them almost touched on but then really did nothing with it.
The Enchantress was a complete misstep for the first outing of these characters, and totally blew the roof off of the DCEU with all of the explicit mysticism and magic. I would include Katana and her sword in that point as well, which also felt like too much too soon for this world. With Katana specifically they could have alluded to what she believes about the sword, but not directly confirm it by showing it smoking as she speaks to her husband's soul. Have the Squad be a little wary of her because of her tendency to whisper to herself and the sword.
All of the floating text during their intro cards felt completely wrong, and Captain Boomerang's "Unicorn fetish" felt like a direct response to Deadpool.
I was willing to give this Joker the benefit of the doubt all through the early production and promotion of this movie, but the minute he first comes on screen they lost me and never had me back. There isn't one moment where he is on screen that feels right to me, and I would be happy to see Leto leave the role regardless of how they explain it.
At this point I believe that the Justice League movie should have just been "Flashpoint" so they can restart and correct all of the stupid stuff they have done with these movies. 3 movies in we shouldn't still be shaking our heads at the huge mistakes they are making, or sitting through movies because we're holding onto the last shred of hope saying "this will be the one that fixes things!"