The Girl Who Died/The Woman Who Lived - I know why you found this a struggle to re-watch. For me this is the weakest of all the 2 parters of this series. That's not to say there aren't likeable parts.
TGWD - A fun enough episode. I like the Viking setting. On the whole the comedy works well. Odin is completely naff. The Mire had potential but have been very wasted. Their defeat was all a little too convenient.
Capaldi and Coleman are excellent. There is nothing special about the support cast (due to the writing rather than performance). I actually like Maisie Williams' character. I feel Ashildr is purposefully meant to be bland to make the character progression more striking.
Although it's nice to revisit why The Doctor chose his face (to remind him to save people) I still can't understand why he made Ashildr immortal. If you go way back to The Five Doctors then for Time Lords immortality is a curse rather than a blessing. So it doesn't really fit for me.
TWWL - A marginal improvement but still below par. It is nice to have a companion lite episode.
The setting and production are great. On the whole again I find most of the comedy works.
Capaldi is excellent. Maisie Williams' performance is great. You can believe she has lived for centuries and all the pain she has endured. There are some lovely interactions between Capaldi and Williams. Again the villain is weak and too easily defeated.
I like the foreboding nature of the ending - Ashildr in the background of Clara's selfie just to remind you.
Not a 2 parter I make a habit of re-watching.