Mambo can be particularly useful if you don't want to do customization, but simply add a lot of pages to your site.

Mambo is definitely the way to go if you are comparing it with Typo3. We found Typo3 to be server resource intensive. Typo3 is also a bit complicated and not suitable for complete beginners of content management systems.

Both Mambo as well as Typo3 seem to have a lot features at first glance. They also look good. If you just change the logo, you immediately have a drag and drop site ready to go. Mambo can be particularly useful if you don't want to do customization, but simply add a lot of pages to your site and take advantage of all the built-in tools Mambo provides.

Customization in Mambo is difficult. We thought that we could complement the great design of Mambo by doing a lot of customization. However, we found that the user-end documentation was alright, but documentation for customization and modifications were not adequate. Looked like many sections of the manual are still under development as of this writing. We wanted to create custom top menus for a client site, but there weren't enough documentation and the time investment was not worth it to understand the programming.

In terms of content management systems, we would also recommend Drupal. Drupal installation and customization is easy and without hassle. Also, documentation is adequate both in terms of user and development requirements. We created a web site using Drupal and it was easy to customize the top-menus, which we had earlier wanted to do in Mambo.

To see how complex sites you can build with Drupal check out: http://www.spreadfirefox.com. It was created using Drupal.