Mark, I like your format. I suggest allowing 45 minutes for agenda creation and marketplace. (Or be aware that it may take that long, and that the 10 am sessions may not get started at 10 am but rather at the "right time".)
I like allowing 90 minutes per session if a full day is available. When they are over they are over, and people find their way into other sessions or to the coffee table. I have used 45 minute sessions during 3-4 hour open spaces which worked fine. Best wishes Jeff Aitken
