Most CMS's tend to be simple to moderately complex CRUD apps, i.e., exactly what Rails and Django excel at. It sounds like you enjoy working in PHP, so maybe t

Most CMS's tend to be simple to moderately complex CRUD apps, i.e., exactly what Rails and Django excel at. It sounds like you enjoy working in PHP, so maybe try Laravel (Rails in PHP) or Symfony (Django in PHP). Symfony even comes in a CMS-skeleton flavor called Symfony CMF.