Still flying high from the previous conference experience, so bear with me 
I've been attending to Plone Conferences since 2014 and enjoying every time. But there might be still room for improvement in one content-related issue: trying to reach the non-technical crowd that uses Plone.
There are plenty of Plone case studies in every conference, but they are usually trickled here and there, in-between and simultaneously to more technical talks. Which is kind of nice, usually every attendee from the Plone community can find something that suits his/her interests.
But what if we changed the flow of the three conference days like this:
- day: the state of Plone, all (or most) case studies, future of Plone
- day: something else more technical
- day: something else more technical
We could maybe sell 1 day tickets (or even keep it free), just to widen the community as much as possible.
And since we usually have three tracks every day, we can keep the technical track in place for the first day too
Another related thing: Earlier this week I was presenting our ePortfolio system to another Finnish university. It is a Plone 4.1(!) based service that we haven't been actively developing for maybe five years and that has been running since 2011. It does have some early build mosaic, but mostly its "just" Plone.
And they were amazed: it was customized, feature-packed, still running smoothly, easy to use and, of course, free of license costs.
My point is: Even if we as a community take Plone features as granted and/or some theming issues challenging, Plone is still very impressive out of the box. And just by showing the use cases to a hopefully wider audience in a one-day focused mini-event, we might gain more traction to the usage of Plone that way.
We could market this especially to the enterprise users (universities, governments) in the country, where the next Plone Conference is held. It might not be easy for a university staff member to get 3-4 days work trip, but 1-2 days is much easier.
In summary: not a criticism to earlier conferences, just an idea for the future 