When researching CMS'es for our new site we knew we wanted to use something based on Rails.
Locomotive's data modeling allowed us to create rich models to represent entites of content, rather than just "pages" like most CMSes. It relies on MongoHQ, which we are totally over the moon over lately for just this type of application.
Rather than create a "page" for each project we wanted to feature, we created a "Projects" model with metadata associated with that project. Then our template pulled that data together with Liquid to generate HTML.
The data model also supports an API from Liquid to not only access data but also create it as well. We're using this for our Contact Us form.
Locomotive has support for pulling JSON data from the web, complete with caching. This makes it really simple to include features like latest tweets in our footer.