[Mediawiki-l] Permissions based on sections

Hi all, I think I already know the answer to this, but I thought I would run it by some people with more expierience with Mediawiki than I. I want to create a wiki where I can create different sections that different groups will use and assign permissions for each of the groups. Think departments in a company and creating different department groups and not allow people outside of that department group to see that department section. page permissions only with sections and while there are some page by page extensions, there is a disclaimer on the ones that require a core code change that Mediawiki wasn't really designed for page by page permissions. I guess my question is am I right in my conclusions? Has anyone had any success implementing some of the page by page permissions extensions whether it be the ones requiring core code changes or not? If anyone has had experience setting up this kind of environment and can recommend an alternative CMS, I would appreciate it as well. Thank you, GT