Being a Microsoft Regional Director has a host of benefits, most of which are intangible and hard to explain to someone who's not experiencing them. The number one benefit, for example, is the other RDs. They're such a smart and fun group, and the connections have helped me personally and professionally. The only drawback to being an RD is that so few people know what it means. They think perhaps we work for Microsoft (nope) or that it's like being an MVP (nope, though many of us are MVPs as well) or that we get paid to do it (nope again.)
Recently Joel Oleson had a crack at it. The phrase "unbiased evangelist" is a little tricky, isn't it? And we're not exactly evangelists either ... Microsoft already has people for that. I would say that we've chosen Microsoft technologies (not always exclusively) for our own reasons (that is, not because someone compensated us directly for choosing them) and we're happy to share our reasoning with others. It's that sharing that gets us the nod to become RDs.