I've used RAML for the past six months, but only to generate documentation. It's pretty easy to learn. A RAML file is a lot cheaper to rewrite, so I write RAML first and figure out if the endpoint makes sense before I write the backend code manually.

I don't know of projects generating the actual server side code from RAML/Swagger/API Blueprint other than the OPs project.

Other than documentation, they are useful for generating mock servers for testing, API client libraries, and collections for postman/paw.