Lets say in this example that I have a cabinet. I want to place a hinge for a door; I am making the hinge a sub-assembly so I can control its configurations of  "Open" and "Closed".

My goal is to show the hinge in a closed configuration.  If I right-click on any part of the hinge and try to change configurations in 'Component Properties', I get properties for the individual part of the hinge sub-assembly.  This means I then have to go chase down the sub-assembly in the tree.  (here is a video showing what I am talking about http://screencast.com/t/XDZxCBFh)

The example I am showing is a small one, but applied in a large assembly this will drive someone crazy.  I used to run into this a lot when working with air cylinders.

If you need any elaboration let me know.