I agree that if you have multiple accounts and you are going to boost, boost more than on character. You actually get more exp per toon by having more people in your party. Make it a full group, put them on follow and plow through, RFC, SFK , RFK, and SM. Once they are at 40, you may want to just take 2 and quest together, or you may want to take them all. But I think the main point is, if you are boosting, the more the merrier.