This is something I have to agreee on, I used Mambo / joomla a for a lot of sites and replaced them all. Personally I think Joomla sounds very clever but it has a horrible backend and somethings are nearly impossible.

Even with the all the expensive components I bought I could not get things done the way I could with postnuke for instance. Right now I'm using a commercial CMS because even wordpress was not good enought. And drupal just gave me a headache :P