The question in the title comes straight from this very interesting post on Kinless' blog. He and his wife are in different guilds. His guild has a raiding calendar and they adhere to it religiously. His wife's guild has a raiding calendar which is completely ignored. Whoever is online at any given time gets to raid.
I would think the more structured guild would be ahead, but the more loosely organized guild is moving along nicely. So nicely, in fact, that both guilds are progressing at about the same rate.
How does your guild do it? Formal or casual? And does your guild's style work for you or are you enduring it to get what you want from the raid?