I'm leaving for a destination I still don't know
I liked both the story and Capaldi's performance as the Doctor, as well as the mystery of Missy that picks up unexpectedly from last year's Bells of St John's (I'm torn between wanting her to be the Master and something new).
In particular I rather liked the Control Node, which tickles my AI fancy just right.
The only thing that bugged me was the troptastic sexed-up buddy breathing shot, in large part because it had been built up outside the episode as "we've admitted theyre married, now they finally get to have an onscreen kiss like all the hetero folks". A strange combination of sleezy and gutless, but thankfully a minor point.
Like all post-regeneration stories of the new series, the Doctor has a tendency of playing second fiddle to the companion's coping with the experience as he beds his character down, so the real test of the new Doctor will come next week.