When Capaldi was first put in, I was furious. Outraged, even.
I'd just warmed up to 11 after discovering 10 early in 11's season and blitzing the prior seasons. I didn't like 11 when we switched to him, too, and then I warmed up to him.
I'm warming up to Capaldi (Dunno how to number him, what with the War Doctor lurking anomalously in the list somewhere,) faster than the other two.
I'm also quite fond of Clara, and I was beyond overjoyed when I heard she was coming back this season, and disenheartened to learn that she's going away.
I liked Clara, because in her, I reckoned, the Doctor had met a match; someone who could retain the point-of-view of the human, but who could, arguably, be every bit as eternal and long-sighted as he.
After all, she is the Impossible Girl. She tore herself apart and flung herself into his own time stream, so as to always be there, right when he needs someone to step in the most. I hope that gets called back to somehow. That, perhaps, Clara is an eternal reincarnator; eternal, ageless, but in a different way to Jack Harkness, the Doctor himself, or now Ashildr; when one falls, another will crop up to take her place, and eventually, she'll remember who she is. What she's capable of.
And with Ashildr, well... I like her, though it seemed like she was really trying to force her callous exterior at times, but at the same time, did the Doctor forget that she's literally a Viking's daughter, daughter of a raider, who made his living sailing over the water to that which belonged to other people? He's SURPRISED that she's more comfortable with bloodletting as a way to get her way than he is?
I also think the twist is that Ashildr isn't a threat to Clara at all. She wasn't menacingly staring at Clara... She's just watching, waiting for the Doctor to abandon her, so she can step in and hug her. Then maybe take her by the hand and take her to the Discarded Companions Club, where they can get a hot cuppa and a stiff drink with Dr. Martha Jones, Wilfred Mott, Vastra, and maybe Strax (if Sontarans live that long.)