Head on over to WebDesignerDepot.com for a great article about concrete5 written by community member ChadStrat.
Chad talks aboutwhy so many developers and designers love concrete5. He writes, "Although Concrete5 is a MVC/OOP centric CMS and has ridiculous power under the hood, the front end editing is the first noticeable aspect of Concrete5: adding a page is super quick."
Creating a theme, finding add-ons in the marketplace, and getting help from the community are covered well. "If you still have questions, the Concrete5 community, albeit smaller than many CMSs, is extremely proactive in helping others," Chad writes.
If you have friends or colleagues who are considering concrete5 and want to know what makes it so great, point them to this article.