Just finished binge-watching the last run of episodes. They did a decent job with the story arc, but unfortunately it set up a lot of things we'll never see the payoff for. Mainly, we still have no clue who Anarky really was. Maybe it doesn't entirely matter for the character as portrayed, but it might've added some substance to the character if he'd had a backstory rather than just being this random, all-powerful nemesis.
Also, Bruce Wayne is still believed dead as of the end of the season. They never bothered to restore the status quo. We'll never know how they would've brought Bruce back. Kind of sloppy to leave that dangling.
Harvey Dent's story arc was handled in an odd way. Usually Harvey is a good guy in his DA days, so that when he goes mad and becomes Two-Face, not only is it a tragic loss but it creates a duality between his good and evil sides. But this Harvey was just a shallow political opportunist. He was "two-faced" in the sense of putting on a public act of being tough on crime and privately not really caring one way or the other, but we never really got any indication for why he'd suddenly come to think of himself as two people once his injury occurred. So that was kind of random.
And sure, bringing in Slade Wilson as Batman's nemesis was a decent idea, seeing that Deathstroke is often seen as a sort of anti-Batman character. But having the Gotham Special Crimes Unit publicly endorse a masked mercenary named "Deathstroke" as their champion of law and order just... didn't work. Don't they have any PR people?
And while it was a nice idea to culminate the arc with bringing the "Outsiders" together, it's weird that the only actual Outsiders they used were Katana and Metamorpho.
All in all, I think Beware the Batman was a nice try, but ultimately it didn't hold together as well as it could have, and the awkward 3D animation often worked against it. And I certainly won't say that the use of previously obscure villains worked against it; after all, Batman: TAS did wonders with hitherto-obscure villains like Mr. Freeze and Poison Ivy, and BtB didn't really handle the prominent villains like Deathstroke and Two-Face that much better than the obscure ones. So it wasn't about the choice of characters, just about the general storytelling. Magpie was handled extremely well in her debut (except for her random, never-explained ability to survive what should be fatal injuries), but terribly in her return. Some villains, like Pyg and Toad, Anarky, or Humpty Dumpty, never really gelled. And Batman himself was a little too unsympathetic. I'd say the most effective characters were Katana, Alfred, and the Gordons. (Tara Strong playing Barbara Gordon is pretty much guaranteed to be awesome.)
I wonder what the odds are that we'll see another Batman series in animation. Cartoon Network doesn't seem to be interested in such things anymore, unless they go an outright comedy route like Teen Titans Go. But who else could show it? Maybe Netflix?