Overall I enjoyed this, but let's start with what was awful.
Worst part of the episode: the Doctor treated Clara like ****. I know he's supposed to be old and tortured and want to keep her safe. I also know that, in terms of sending her away, Nine did a similar thing with Rose. But with Rose, I had the feeling that Nine really cared for her, and what he did seemed like a calculated decision looking out for someone's best interests, whereas with Clara it just felt like he was casting her aside. The whole episode (in fact, throughout her whole arc) Clara just kept helping the Doctor over and over and he kept throwing her under the bus. Also, what was with him telling the Daleks to go ahead and kill her? We got a bit more clarification when Clara said "you'd kill me anyway," so I suppose we're expected to assume that the Doctor had a similar mindset in saying that, but it still felt really dickish and not at all like the Doctor.
There were also a few sexist jokes, and a few sexist plot elements, of course, because it was Moffat and Moffat does that.

Examples would include the whole "now THIS is a woman!" crap, as well as basically the entire Church of the Papal Mainframe arc. Like, this lady, Tasha, who we're supposed to assume the Doctor was involved with at some point (because in Moffat's show the Doctor has to be involved with freaking everyone), just straight up rejects her Dalek hijacking? How? Through the power of magic Doctor love? And was she good or bad? When did she switch back and forth? Pretty sure she was being an *** to the Doctor before she was ever hijacked by the Daleks, so why did saving her from the Dalek save him from her?
Oh, and
what was the deal with the turkey? Like did they just realize it needed to be exposed to heat? They didn't really use the time machine as a time machine, just as an oven. Whatever.
Regeneration felt forced. Plus, Moffat seems to be forgetting about the fact that River gave the Doctor her regeneration energy. Why not just use
that to let him regenerate? It might bring a tiny bit more meaning to the train wreck that is the Doctor/River relationship. Wiping out a planet full of creatures, even evil ones, does not seem like something the Doctor would do, but I suppose after centuries of watching them kill your friends you might get a little ******.
Now, for what I think redeems the episode: the Trenzalore arc was excellent. Watching the Doctor grow old and sad and continue to fight his enemies was brilliant, and it added some much-needed depth to Eleven. Moffat's always trying to play him off as the "tortured Doctor" when he really just isn't, and this gave him a reason to actually be upset and angry. Tying in the Silence as confessional priests was a great bit, I doubt it was planned but nevertheless it works (and much better than some of Moffat's other stupid retcons, like in the Season 5 & 7 Weeping Angels episodes).
Looking forward to Capaldi!