My opinion is that if the guild is short on people for an encounter, then multi-boxing should be welcome IF the fight is doable for a boxer and the player has proven themselves in something like Kara. However, I don't think multi-boxers should take the spot of willing people if they are available to raid. I am both a boxer and a raider and I would never want to deny a guildmate a raid spot by my boxing an extra toon.