I liked that it didn't feel as convoluted as 11's series finales did (seriously, I'm still not entirely sure whether I didn't understand all that Silence stuff or if it was just a massive let-down). Obviously, I'm kinda sad that the person who died never got to achieve that new entry to their bucket list. But the Danny stuff was wrapped up a lot better than I thought it would, and it feels somehow right to have Clara leave on such a bittersweet note.
The only big "oh, is that it?" moment for me was with Missy's comment about why she hooked Clara up with The Doctor. She thought Clara was perfect companion material. Is that it? That's underwhelming.
As for the entire series, well there was no doubt that there were some stinker episodes, and much as I like the way that Clara and Danny's plot threads came together in the end I'm not sure that completely makes up for all the other episodes where I was bored to death of them being killjoys. Rather oddly, taken as a whole this series was not about The Doctor but about Clara, and I don't think that's something I'd like for them to repeat next year. It's the first series of a new Doctor, why are we exploring the companion and not him? I still don't feel like I really know what he's like. But it ended on a high so I look forward to the Xmas episode and the next series.
Just an aside, but it's also worth mentioning that this series had a new timeslot here in the UK. On the one hand, it's nice to see the 'beeb' treating the show as the centrepiece of their Saturday night schedule (which IIRC they did for 9 and initially for 10, before bumping it to an earlier slot for the tail end of 10 and all of 11's run). On the other hand, this series got better as it went along, and yet the last few episodes clashed with the new series of The X-Factor (which is HUUUGE over here) and so the episodes towards the end actually saw a ratings drop.