All that said, the tool is helpful when used in moderation. If you find that you're needing to use it often I would say you need to revisit how the family is built, or how you're manging your family types, categories and subcategories.
Where I see this tool being particulary helpful is in detailing. It always drove me crazy in Revit that you either had to build detail components with all sorts of additional subcateogories (which made it hard to manage) or you had to use the linework tool to get detail components to look just right, and then, depending on view scale it might be even more difficult to manage since in one scale the component might look right, but in another not so much.
Now with this tool the problem is solved. You can quickly drop a component into your view (that you're detailing) and quickly adjust how the component looks in that particular view. Since we're dealing with detail components, I'm actually completely OK with having their graphic appearance be completly unmanaged. Since they are 2D elements they're not real model elements, so we're not depending on them from a database stand point, we only want them to look good in the detail view we've used them in.