My trip to Huzzah! was a little nerve wracking because this was the fourth convention that I would be running a game at. My previous three attempts were unqualified disasters but I was determined to not be the Charlie Brown of gaming. I decided to go to unprecedented lengths. I playtested the game, I used a popular ruleset, and I finished the terrain at least 40 hours ahead of deadline.
I ran a scenario from Commands and Colors Napoleonics using their "epic" rules. The hope was that there would be a lot more activity on any given turn and less player down time. We used the Salamanca scenario without Portuguese mainly because I didn't have time to paint any Portuguese. In the end I'm happy to say the players were pleased and the game was a big hit.
The main factor behind the event's success was probably good natured players. The rules are good ones for convention use as well- turns are fast and usually two or three players will be active at a time. Movement and combat are fast and there are no ambiguities to cause fights. Further, most of the rules are intuitive so you rarely hear cries of surprise and complaints about not knowing some esoteric mechanism. Finally, the ten millimeter scale makes large armies look just terrific on the field. Any smaller and they become indistinct, any larger and they lose a sense of numbers.