I played twice over my short weekend at gencon (thurs/fri). Short summary of my experience: new characters are interesting, scenario one is very hard, event staff was enthusiastic but not very knowledgeable. (I won't be expanding on that point because I don't want to harsh on volunteers, but two out of the three I interacted with seemed to me to have a poor grasp on the rules. Last one was very good.)
First night I played Kyra at the last session of the night. My teammates were a shaky Ezren, a ok Wu Shen, and a good Valeros. Ezren died with about ten turns remaining, exploring into 3-card location, one of which was known to be the villain, with any attack spells. Wu Shen almost died, I spent like four-five turns trying to closing a divine 8 checkwith 1-2 haunts stuck to me, and Valeros pretty much saved the day.
Second day I played midday as Bekah, who I quite enjoyed. Pretty solid group of the gnome fighter and sorcerers (husband and wife players) and radillo. Very cooperative group, very ready to spend blessings on each other. That might have been our downfall, actually, because we lost on time with about two and a half locations to go. Radillo died, and the gnome sorcerer came close, but I finally cured her back up.
My main takeaway from organized play is that I would anticipate having to replay scenarios quite frequently if that first one is any indication of the difficulty level.