joomla

I spent several months learning Joomla and built 75% percent of our new district site using Joomla when I happened across Drupal. I was hoping to get some feedback from the community from anybody who has used Joomla and now uses Drupal for their district site and why. I am working through the O'Reilly Drupal book right now and really like Drupal but I wanted to "test drive" both CMSs in hopes of making the best decision on what system will work best for our new district site. Please let me know your thoughts if you have used both CMSs and why you chose one over the other. Thanks!!