Finally a decent looking Rails CMS system that looks usable: Radiant CMS.
Haven’t really gone down the Modx path yet, so I’ll look at Radiant instead as rails is my prefered web platform. Looks a big rough around the edges at the moment, but has a usable first version. Couple things I’d probably like to see as major features for my requirements are: i) some sort of assets (pictures, pdfs, or other static files) management interface and ii) a WYSIWYG editor.
The first I might even add myself if the code looks easily. The second is probably just a matter of time.