It definitely needs an injection of something, although I think this series is more of a problem of not being sure how to position the show and Capaldi.
I get the feeling there was some pushback on the darker and more character heavy series 8, and in retreating from that the show has got a bit lost, whereas it seemed quite sure of itself last time round. Even with the expected missteps.
The show's fallen back on gimmicks really, the sonic sunglasses, the guitar, and yes the 2-parters which have hindered the stories more than helping them. Even the cue-cards, which before was an ever present aspect of his personality and part of the stories in his relationship with Clara, just appeared for a joke and then this supposed side of him completely disappeared again.
There's nothing holding it all together unlike last time, and it's frustrating because Capaldi is so damn good at making the best of whatever he's given but he's just not being given the best to work with. He's managing to be my favourite Doctor just for being Capaldi, if that makes any sense.
Clara too should now have been this addicted to travelling, thinking she was the Doctor, and putting herself needlessly in danger character setting up her exit. Instead she's just back to being just there again, with just hints here and there, and turning evil for a story rather than any ongoing development.
Even if the finale is spectacular, the word hybrid has amazing significance, and the whole series turns out to be back to front, I can't help thinking this series would have been a lot better if it had just carried on the way series 8 was doing things.
I don't mind the glasses or the guitar-I actually like the "flavor" being added to 12-it will give me something iconic to remember him with-bow tie, cane, question marks, scarf, etc.
The problem just seems to be that it's not "fun"-again, the shows aren't bad-it's just dry.
My wife can't watch the show any more because she just misses Matt Smith so much and can't deal with Capaldi. I think Capaldi is the best actor to have the role-but it's just that his stories aren't as memorable. My favorite Capaldi stories have been Listen, Flatline and Last Christmas.