I am a PHP programmer and have written / worked on several sites using both systems. Check it out: http://www.decidebetween.us/web-development/content-management-joomla-vs-wordpress.html
It's a great article. However, I don't think Joomla costs too much more, contrary to what your article says.
Well, people billing themselves as 'Joomla Programmers' tend to bill high, and regular programmers will bill high because they need to wade through the Joomla api. There are also a lot higher percentage of comerical Joomla extensions.
I don't think it gives an accurate picture of Wordpress. I work with wordpress every day and its CMS features cannot be compared to Joomla. In order to get Wordpress to act like a true CMS you have to dig into the code. Joomla can give you incredible features by uploading extensions and clicking a few buttons. Yes the interface is not as simple but once you learn it theres alot you can do. I love the simplicity and elegance of Wordpress but it does limit what the normal person can do with it. Its just that a lot of people don't really need a full CMS. Apples and Oranges.
she put it very well... cms's like drupal or joomla have tons of room to grow where as wordpress is very limited as it was never meant to do certain things... after all its a blogging software