Actually, I've changed the way it works since the first time I posted as a result of player feedback. So, now it works more traditionally where each character is controlled by the player who created that character. I was worried initially that the game would move too slowly if handled that way, but actually it's worked really well. We usually do 1 or 2 moves a day. And the characters are really consistent, moreso than they would be if controlled by a group.
We've only had one player quit the game so far since we started, which is pretty normal for this type of game, and luckily a new player came along to take over the character and it worked great.