I think you are confusing the qualities of a good public API and a good internal/private one (for application architecture purposes only.) For internal, I belie

I think you are confusing the qualities of a good public API and a good internal/private one (for application architecture purposes only.) For internal, I believe REST is the way to go, no contest. Externally is a different story. You would typically only expose a subset of functionality, use different authentication schemes and use a format that can be more easily accessed across domains like JSONP.