I've got a full 8 characters and play all of them with different levels of frequency, but I can say that my "main" really depends on what I'm doing and what my party needs. I prefer different characters for different classes over dropping them all on one (strange for this game? maybe, but I like variety, and I've always loved making as many characters as possible in MMOs), so...yeah, it's pretty easy to have multiple mains. Doesn't have anything to do with ilvl, for me, they don't have to be exactly the same, it just depends on how often I play them. I know plenty of others in the exact same situation who wouldn't pin down a "main", either.