I would not use any old travel agent for a Disney trip. There's too much involved. Unless you're extraordinarily busy and don't really have time to sit on the phone with Disney, I say do it yourself. The only exception to this is AAA. If you are a member, it's worth booking through them for the extra perks. Unless you are the type that changes their resort every 5 minutes, then there's no reason not to. As for booking a private home, most travel agents will not. As PPs have said, they are paid by commission so private listings/rentals and some time shares will not pay commission. The only exception to this would be is if they are renting it out through a company but even then, a TA might not want to mess with it. TAs rely on commission, kickbacks, promos, and friends they have with different vendors/brands. If it's something they aren't familiar with, they might not want to get involved. AAA is just a much of a travel agent as any other... IATA certified, paid commission, etc.