Use Meetup.com or Facebook Groups or other?

I’m a co-organizer, about to become organizer, of the WordPress Hampton Roads Meetup group (http://www.meetup.com/WordPresshr/). I’d like to hear from others the pros and cons of just creating a Facebook group or maintaining a self-hosted site or using some alternative service for growing, organizing and communicating with the group.

I think Meetup’s fees are steep for what it’s for, but if it’s the best or the recommded online vehicle by the WP/WordCamp folks for WP user groups then I’ll keep it as is. I can recoup the fees from members with a nominal charge.

So what say ye?

Thanks,
Melodie