I'd prefer the hierarchy to behave as a directory tree. If I assign a link to a subcategory, it shouldn't be displayed as being a direct subnode of the parent/root category. I turned off the "Include Links From Parent Category" choice in the widget to solve this problem, but now I can't add links directly to root category - they are hidden along with links with inferred membership. I'd guess this is related to the problem mentioned in FAQ. Otherwise, good work, just what I needed.