Let's face it - there are good and bad points to guild size, either big or small. In a small guild everyone pretty much knows everyone else and has a fairly good idea of everyone's skills. In a larger guild you're one of many. While this can be problematic when trying to keep up with what's going on with everyone (if not downright impossible) big guilds also can help greatly when you're looking for people to run an instance - either smaller or raiding group. Why bother looking around outside when you can just recruit from your guild?
There's more, of course, but this morning we thought we'd ask you - which do you prefer? A small guild or large guild? Why do you prefer that guild size? What do you think are the biggest bonuses and drawbacks to your favorite?