Last year we used the wiki and actually presenters and organizers were happy about the system. If we go for something different at least it would be good to know what problems found last year are you trying to address.

Three tracks, yes. What about thinking by default on users (big room), app developers (medium) and platform developers (small). We can always adapt for specific cases.

Lightning sessions with everybody in the room are proven to be successful and are also a way to canalize presentations that didn't make it as own sessions.

We can also think about 2-4 keynote sessions in the two community days. If we have speakers with the guts, the skills and the content.

The medium and small rooms are next to each other with a common door from the outside. The big room is 1 minute away walking a straight line in the park. No crossing streets or anything.