"Smile" was interesting. It felt like a classic series episode in that nothing happened for the first couple acts. Except, in this case, that was done so we could explore the relationship between the Doctor and Bill. And poorly done, too, because then the final act was a messy race to tie everything up.
Exploring a relationship between the Doctor and a Companion is also a mistake. We're supposed to be thrilled that Bill asks questions "that the audience always wanted to ask" like how much does the TARDIS cost. Ummmm... A sentient machine made by a race of gods? On a show that's been in the public conscious for 54 years? That's actually not the question the audience is asking.
But, oh well.
Rumor is that Pearl Mackie got herself fired because she was a nightmare on set, thus her one season. She's not even carrying over to the Christmas special. So that also makes everything seem a little hollow.
Overall, though, Capaldi is the sort who can carry any story on gravitas alone. So I was fine with "Smile." And also reminded how fucking awful NuWho is and how we're probably doomed because the next Doctor will either be a publicity stunt or a dud.