I like that what has won Bill her place in the Tardis is not that she’s a mystery, or that she’s somehow ‘earned’ it in payment for saving the Doctor’s life, but just that she’s clever and curious and has potential and she and the Doctor get on so well.
Completely agreed. And I think it's an important base note to get back to. Clara's run was kind of amazing, but it really backed the show into a corner w/r/t companions. I'm glad Moffat got one more season so he could set us back to a reasonable standard of companions worthiness.