About the only thing worth it in RCI was Hilton Vacation Club and Hilton now charges $35.00 a day in resort fees for exchangers, so not worth it (I am surprised Hilton hasn't started charging for just standing in their lobby!). I would rent the DVC points out and pay cash for where you want to go. Or better yet, buy only enough DVC points for onsite trips and pay cash for the other trips.
As others have said, DVC has a Hilton Head property that you can book direct with DVC points.