The Doctor Falls / No More - What did you think? (River Song's catchphrase)
-----------------SPOILERS!-------------------
Since spoiler tags don't close properly at the moment consider everything from this point forward a spoiler. Don't say you were not warned.
[spoiler]Would you like a Jelly Baby?[/spoiler]
I really enjoyed the episode, the biggest weakness for me was the whole Nardole (Now with added backstory!) is upstairs waiting for the already very well developed Cybermen to evolve at a much faster pace again and come back and wipe out those kiddie winkles and his love interest within the week. Sure The Doctor could always fly back in his Tardis and save them but that particular story wasn't wrapped up by the end credits and would detract from the Christmas special. A computer virus timebomb which meant the ending still went the way it did but would eradicate the Cybermen an hour or two later would have resolved that.
Now, onto the good stuff!
The Missy/Master storyline was very nicely done. Not only did neither Simms or Gomez not back down or steal the other's limelight but both presented someone who normally, with any other character in a scene, would be the domineering force that The Master/Missy is - a great pairing done with graceful acting. Great jokes thrown across the gender divide by both and I finally got a bit of Bill and Ted logic thrown in with the macguffin for their Tardis to be repaired. Enough room to work around that beautiful suicide/backstab for a future writer to have (If need be) but also works elegantly as is. I could have done with more of them but I know that's down to my gluttony rather than appreciate of the finesse presented.
PART 2 below!