Okay, I'm a bit biased, but I don't think Mr. Brown comes out of it terribly well - he doesn't really respond to a lot of the points Dan makes, and a lot of what he does say boils down to "stop trying to redefine marriage" (which, as nobody is actually trying to redefine marriage, is a really daft argument, but it's become increasingly popular over the past two or three years).
Dan, on the other hand, seems courteous, erudite, intelligent, thoughtful, and all things considered the sort of guy I'd happily spend an hour with over a pint* down the local pub.
It's a long video - over an hour (I thought Youtube used to have a 10 minute limit?), but worth it if you're interested in the subject matter, not least for the moment when Mr. Brown (discussing divorce) says, "just because you believe something is wrong, it doesn't mean that you make it illegal," which rather charmingly makes mincemeat of his anti-same-sex marriage argument, and also is going viral even as I type.
*of Lemonade, of course.