Small Groups vs. Large Groups

How large is your RPG group? Small? Large? Average? What are the ramifications of each size of group? Do you have too few players? Too many? It all depends on what you're looking for in your games and sessions. Back in early high school, the largest group I was part of had 15 players and 22 characters spread across those 15 players. Joe, our wonderful GM, ran it all with ease and style. He did have a co-GM sitting at the far end of the table to wrangle the players and help keep them focused. Joe made all final rules arbitrations, but if a rule was clearly written (kinda rare in those days of