This module is fantastic. It is very surprising that it is not a core extension. However, I am having issues with using the core Joomla SEF turned on. When I go to an article, and I am using the expandable menu, the little + and - images break. It has something to do with the category being written into the name of the URL. I have hunted around to figure out how to address this, and cannot seem to figure it out.
Otherwise, this module is truly excellent.