I made all decisions in pencil and allowed anyone wanting to the opportunity to change them. That seemed to be a nice compromise. I was surprised how popular the 'grab and go' approach was - few people changed anything.
The only real snags I hit were mismatches of expectations. There was a table with one person wanting a fantasy setting that takes itself seriously, and three piling on puns and anachronisms. My last table of the con was the toughest - there were 5 players at the table, representing at least 3 different creative agendas. I don't think the kinds of problems that table had can be addressed in game design, so it's more a hazard of throwing random strangers together than a problem specific to Dungeon World.
The two players who did more than one session were very surprised with how differently everything played out. I tried to explain that it is a situation to handle in your own way, not a script of encounters handled in a set sequence.
The only time things got clunky / wonky in handling mechanics seemed to center on A) the lack of a formal initiative system or B) rolls to aid or hinder another party member. Before I derive any criticism for the game from that, I'll have to go back and see if there is something I misread in the actual rules.
Speaking of actual rules, I read them front to back between my test drive game at home and the con games. (OK, maybe I skipped most of the monster definitions). I had the pdf on an ipad for reference, and in 6 games, I pulled it out to search the text twice! I did have double sided basic moves sheets printed, and a GM cheat sheet prepped, but still - that is amazing. I think you have a very consistent and intuitive (once you've grokked it) rules set.