Are there specific elements of SXSW that make it a successful conference?
My answer to Are there specific elements of SXSW that make it a successful conference? on Quora
SXSW is a great event because of the people who go. There is no other technical/creative conference I can think of which attracts talented, interesting people at the same scale (20,000+ attendees).
Part of the secret here is the reason many people complain about SXSW: the panels. A majority of the sessions on the schedule are panels with 2-5 speakers. These often aren’t as well planned as a solo talk (running a really great panel is actually very hard, see What are some tips for moderating a panel?) but that’s OK: the real purpose of a panel is to get those 5 people to come to Austin for a week so that you can talk to them in the bars afterwards!