What Peter Capaldi brings to the part is intensity, Scottishness and a hint of the fragility consonant with his relatively advanced age. In this first episode these characteristics were in flux and had yet to settle and coalesce, but he has said in an interview that he meant it to be that way so not to worry. Look, he's one of the very best actors we have. I trust him.
Jenna Colman is a fine actor- and very good in this episode but I've no idea who or what her character is supposed to be. We know more about the Doctor's antecedents than we do about hers- and isn't that entirely the wrong way round?
The story was the usual silliness. There was nothing we hadn't seen before: dinosaurs, Victorian London, cyborgs. We got to spend a fair amount of time with Madame Vastra, Jenny and Strax- who are fun- and were given a glimpse of a new super villain (or is she?) played by Michelle Gomez. The fight scenes were rubbish. There was some chewy stuff about identity and masking.