I do have friends that play on other servers, and while I do have characters on the servers they play on, I still prefer to play my "main" on Leviathan. I also have more friends on Leviathan where-as I only know that one person on, say, Adamantoise, Excalibur, Behemoth and Balmung. Though I have offered to them that if they were to decide to reroll/transfer to Leviathan, then I would happily invite them to my FC.