Just discovered I have no review of this one. I guess partly because I wasn't very active in fandom (apart from RP) at that time, and partly because I didn't always like it that much. I always liked the ending, once it's just the Doctor and River, but the early part with Hydroflax always felt boring and awkward and forced to me, and that's always affected my view of the episode. I also didn't like Nardole, not until midway through the following season when I completely fell for him, and now completely love him in retrospect too.
But I just watched it again, for the nth time, and it's really funny! So many, many wonderful moments brought about by the pairing of two such brilliant, comic actors, and while some of the things River does still make me cringe, there are also moments like the Doctor 'finally' getting to do the "bigger on the inside" bit, which is absolutely hilarious!
And once you finally get the *actual* pairing of River and the Doctor (i.e. once she's finally realised who he is), you have that fantastic partnership like when she's fighting off Silents with Eleven, quipping and planning and fighting for dominance and so much love, and it's such amazing fun.
And then there's Darillium. The Doctor leaving her knocked out and getting a restaurant built, just for them. The whole gesture of it. The twenty-four years thing. And just the fact that here, now, finally, you have the two of them more or less on the same footing, both knowing it's nearly the end for them, save for perhaps one or two more one-off meetings. It's beautiful. I love the fact that they both get to be happy together, and then say goodbye.
I also love the fact, which I don't think I'd ever really 'got' before, that the Doctor really needs this, needs her, in the wake of everything he's just gone through. He needs time to heal. He needs to know that even though he's lost Clara, he has someone else who understands him and loves him just as much (and probably a whole damn lot more) as Clara did. Someone who actually has a lot of the same qualities as Clara – the love of adventure and daring escapes – but is perhaps a better equipped to deal with them, although she too ends up sacrificing herself for the Doctor.
But he gets to have those twenty-four years with River, which is perhaps what he was trying to have with Clara. At least he gets them with one of them.