Re: A great episode
This older doctor? More badass than the rest? I fear you're not looking far enough into the past.
Capaldi's currently just about younger than William Hartnell was at the end of his tenure in the role, and not a lot older than Jon Pertwee was when he left. Both of them were (relatively speaking) somewhat badass from time to time, as it happens - and you'd've guessed they were both a fair bit older than Capaldi currently is. You could argue that with a middle aged badass Capaldi in the title role, Doctor Who is returning to its roots...
(and as for badass in recent times - well, Christopher Ecclestone and David Tennant's versions of the Doctor both scored very highly in that regard. As did the War Doctor.)
Admittedly, the boy Matt Smith excelled as the Doctor if you ask me. Aside from all that, this latest episode classes as "Boffo, a good one".
Capaldi did well - nearly an hour, acted almost entirely solo. Not perfect, but it worked out well. Very little about it grated or irritated, and I can't wait to find out what happens next.
(My confession: I don't recall seeing any Doctor Who episodes on first broadcast before Jon Pertwee and Katy Manning's time. Yep, I'm about a decade younger than Capaldi.)