Another important factor is how easy the system is to use – most likely, the people you’d like to update the site won’t be that technically comfortable, so the best solution is one that has solid usability.

no. That is the biggest myth of CMSs. Most of the time, the real issues in content creation are around people and processes, not the technology. You need to manage your content creation like any other project – with a clear workflow and timetable, and enough people—with the right skills—to handle what you need to create. The CMS will help you get the content on to the site, but the much more difficult challenge is creating it. And computers don’t write very well.