Some particular character points: I was impressed that they didn't fall into the temptation of making Edison a straight-up villain. In his argument with Tesla he presented a valid argument. When his employees were killed his reaction recognised their humanity, not their profitability. And he got probably the cleverest moment of the ep (clearing the streets). The writer is clearly on Tesla's side, but she plays fair.
I liked the Doctor in this ep too. There's a comment I came across that Tesla was the perfect figure to meet the 13th Doctor, because they're both basically intelligent, sweet and ineffective. That whitewashes Tesla, of course. Interesting, though, that I think that it's not true of the Doctor in this ep either. She was pretty effective. Also, she went the "one chance" route, without even clearing it with the companions first (as per Resolution). (Not much different from the Tenth Doctor, really.) It's a bit odd that copyright infringement is her line in the sand, but there you go.
This gets tricky. The Doctor needs to be effective. The Doctor also should be distinctive; every incarnation has its own flavour. Here the Doctor has an impact, but in the process, compromises her distinctiveness. She succeeds, but as another incarnation would. (I contrast it to It Takes You Away, where she succeeded on her own terms.) I think it's a net positive; stopping the monsters is in the show's DNA, and personalities can evolve. But right at this point it's just as well she's still the Inventor Doctor, so she still has something.
Casting: Goran Visnjic of course was very good, and he and Whittaker played well off each other. Edison was played by Robert Glenister, whose brother played Gene Hunt in Life on Mars/Ashes to Ashes. This is not Robert G's first time on Doctor Who. He also had a supporting role in the highly acclaimed Fifth Doctor adventure, The Caves of Androzani. Oh! And the Queen was played by Anjli Mohindra, who was a regular on the Sarah Jane Adventures as one of the plucky teen adventurers.