hanging out on the top of buildings to brood while wearing long dark coats

Hee! I don't watch Buffy/Angel enough to have thought of that, but what a perfect comparison. And RTD is a huge fan, isn't he? I'm sure the similarities aren't coincidental.

Also, when you're over-tired and cranky? Owen's voice is definitely the most fun.

I can see that. Owen's sarcasm would certainly come more naturally to me than, say, Ianto's dry humour. Of course, I'm just not clever enough to write Ianto's dialogue. Which is why I can't wait for you to write more of him!