From my perspective, the "conversation > pitch" line is key. I love walking around, talking to people, and watching in awe as they excitedly demo their hacks. But it's pretty irritating when everyone tries to sell eachother their apps.

For that reason, I’m a fan of the science fair-style expo. It has less incentive for self-aggrandizement compared to onstage presentations. Hackers can be more genuine/playful without that single, high-tension Demo-athon pitch.

But then again, I have no idea how difficult science fair-style events are to coordinate. I’ve never organized a hackathon.