I really liked Jackson and Rosita. Either would make an excellent companion. I would totally watch them again. I was pleased that, at the end, the historical setting is reified when Jackson says of Rosita that his son will need a nursemaid. He may be a cool guy, but he's of his time. I'm sad Rosita didn't get to go in the TARDIS, though. Maybe after the episode ended? Or did The Doctor leave her ignorant, since she didn't have any of his memories as Jackson did?
The villain, Miss Hartigan, was awesome. I loved her voice--so dark and sexy. And the many layers of her character, especially her anger at the men who held all the power. I was bummed she was killed at the end; I would totally have welcomed her as a recurring villain. Also, her red dress was the bomb. It looked gorgeous on her.
Adored the Giant Robot Cyberman.
I guessed Jackson's story before it was revealed--when his wife's death was revealed, I actually thought there would be several kids who'd been killed. That it was one kid, who survived, might have to do with this being a Christmas Special!
I was actually surprised at the end when the Doctor actually went with Jackson for the Christmas meal instead of sneaking off. I was expecting him to sneak off until the moment they walked off together. I guess, since he's already wiggled out of gatherings in the previous specials, this was the only way to surprise the viewers. Also, perhaps it indicates that losing Donna was that much harder? I really liked that little emotional bit, when The Doctor speaks of her.
It's an interesting mirroring, this episode and the end of last season, with the single-hearted Blue Suit Doctor. I need to think on that.
I think my favorite bit was Jackson's screwdriver.