Drupal fails on such elements as Shopping Carts, Event Calendars, Document Management, and Themes. The majority of these items are functions or features which are considered lacking in the Drupal CMS. Regarding the other CMS, Joomla fails to deliver in such elements as user permission, content management, multi-site management, and standard's compliance. Joomla fails in elements that are more architecture centric.
The main plus Drupal offers in comparation with Joomla! (even 1.5), are unlimited section/categorisation, SEF url's that just work, and, answering your question, granular control of users, groups, and permissions.