People are saying to run the roulettes with a full FC party but that's not a sure fire thing either. I've run an expert with a 4 person premade and had one person just drop the dungeon without a word on the final boss. In a premade you can't simply look for a new member and we tried but couldn't three man the boss, so we had to abandon. Needless to say, I have never run anything with that guy ever again.