I like the opening credits animation, didn't like the instrumentation (too whiny). Loved Capaldi as the Doctor, didn't like (but understand why Moff wrote it this way) the big discussions about him not being Clara's boyfriend and how he is still The Doctor even if he's old now (hint: it's aimed more towards the fans than Clara as his companion). Didn't like Smith's reappearance; it cheapens his goodbye, coming back so soon. And while everything is possible with timey-wimey, it seems like too much 'foresight' for the Doctor - why should he care so much about who he might regenerate into that time, when it always worked out before? Did he mistrust Clara THAT much? Wasn't she the girl who "spent her existence" for him? And now she's being treated like some throwaway companion who only sees him as boyfriend material. It's like Martha all over again (lul sorry).
Good job as usual with the monsters and the creep factor. Loved the reference back to The Girl in the Fireplace, which I suppose was Moff's first real crowning achievement in Doctor Who. Some of the dialogue was quite snappy. But as usual with Moffat, there were far too many mistimed/misplaced immature jokes (ESPECIALLY the one where Vastra closed the carriage door with the stupid beeper while the Doc was upset about the dino). He really likes to frame relationships in a pretty immature way too. He's like a big child. I honestly picture him giggling like a 10 year old boy about some of the shit he writes into these episodes. Well, that's my biggest beef with him, and I suppose it's unavoidable because that's just who he is.
But honestly, if I were Clara, I would leave and never come back after being abandoned like that when they were under the restaurant. Fuckity-bye indeed. "Welp no sense letting them catch both of us" and just leaving her with no instructions and no "I'll be back" seemed too callous, even for a newly-regenerated Doctor who was off his head. Just fuck that shit right to hell.