My gripes:
I get that this is supposed to be a loose interpretation of the real world but top at my list of gripes is the existence of a serial killer convention. I mean first of all I don't think there's hundreds of active serial killers to this day and if there were, I doubt they'd all converge for a convention. (on reflection, I guess that they do explain that the Corinthian's presence in the real world inspired a wave of serial killers, but the second part of that sentence is still a relevant issue, why would these serial killer's so brazenly and publicly gather in one place?) Second, the present day is the technological age, and you're telling me 300 serial killers could converge in one location without a single tip off to the police? I liked Dream's punishment and it couldn't have happened without that plot element, but it still felt really silly. Idk if that's from the comics but man I had to stretch my suspension of disbelief even in this mythological/magic based series.
Again, I don't know how reflective of the comics the show is, but the episodes weren't quite as compelling after Morpheus resolved the Ruby. The show crescendoed with that excellent diner extended sequence, had a really solid foray with Death and then the Hob storyline, but as it delved into the stuff with the Vortex it felt more convoluted, lacking a bit in narrative nuance and commitment to its themes, and just ultimately not as compelling. Though the stuff with the vortex blurring the lines between the waking world was a bit neat, if not fully fleshed out.
While the Corinthian was a really compelling and fun character, I don't know that they expanded on his story and purpose well enough. Just a rushed expo dump at the end before Dream offed him.
Have I mentioned how silly a serial killer expo/convention at a hotel is?