Ok, just seen the latest episode. In a word: awesome. Seriously. I seldom get teary eyed while watching movies or tv series, but I did in the end here.
I'd love to talk more about it, but should probably wait until more people get to see it. As far as non-spoiler stuff goes - it was a pleasure to see this doctor have a moment of genuine anger (even if very brief), something he couldn't really do convincingly until now. Also, this episode uses the angels the way they are meant to be used, as something lurking in the shadows, not in-your-face monsters.