I was an organizer for a large group for professionals in New York City for a few years and WILL NEVER attend another Meetup anywhere again. Professional events resulted in such cruel and psychotic behavior that we even had to call the police at several events. Restraining orders, having to court, etc.
I completely regret all of the time that I spent trying to put on quality events. The stand up comedians here in NYC have it right - Meetup is for LOSERS who cannot meet friends in real life.