Sorry to self-promote, but I'm the creator of a Drupal competitor that may be worth looking at for you: http://www.sitellite.org/ http://www.sitellite.org/ It

Sorry to self-promote, but I'm the creator of a Drupal competitor that may be worth looking at for you: http://www.sitellite.org/ http://www.sitellite.org/ It's a mature project (9 years old, so yes there is some cruft, hell PHP 4 was brand new when it started!), but doesn't have the same community size as something like Drupal. It does have a clean UI, decent documentation (manual, courses, API reference, etc), several dozen modules, and while there is a developer learning curve, it's really flexible once you get into it.