Oh man, as I said above, this is one of my favorite Who stories ever, and I think everybody should listen to it. I definitely encourage you to give it a listen - Gatiss does a great Master, and Alt!Three has some good moments. Also if you are at all interested in China and Hong Kong, the politics in play are fairly well-represented, but not too intrusive if you're not interested.

/blabbering. Like I said, I really like Sympathy.