I agree, hard to make a final legit personal feeling about it at this stage with what we've been shown. I could be surprised with the final execution. The whole concept to me was "what does Gotham look like under the lense of Scarecrow toxin" though I can't recall if I imposed my own view there or one of the Sideshow creators said that in their video. So looking at the Joker, under the influence of the gas, you see his history imposed on him. Batman is a monster, Joker is...a malevolent chaotic entity? Skeletal or supernatural in some way? It didn't come through as strong as the execution of Batman as a horror version of Joker imo. Looked like Joker when he was sick in Arkham City with some creativity in his clothes.
I'm trying to imagine it more like souls or victims of those in his wake weaved into his clothes and body. I'll like it more if we see some those iconic moments in his history coming out of his skin, or in his hair...like faces in Freddy's chest. I don't see that so far though. I won't fully judge until seeing the final product but really it boils down to it hasn't grabbed me like the Batman did or what I think is possible with other characters.