I was contracted to finish off and add some extra components to a website that was developed in CMS Made Simple. In the past I had come across CMSMS and looked at it.
I was also not completely sold on it as a number of the templates and stylesheet code was/is stored in the database. This definitely makes it easier for the enduser to make modifications to these on the fly, but most endusers really are not interested in this and do not have the skills to, that's why they have contracted the work out. The issue I find is that you do not have any version control of any changes to these files, you do have a log of which file was changed by who, but I do not see it providing a diff between these changes.
I believe that in upcoming releases they may be moving these files out of the database, so that would be an improvement to me.
The system definitely has a large number of modules that can be easily installed and there is a nice delivery system provided for those. Although it is hard at times to determine whether or not the module is solid and still being developed. As with most 3rd party development, the developer always starts out with good intentions, but may not complete the project.
All in all, once I got the understanding of the system the changes were relatively straight forward and mamaged to do what I needed to for the project.