I've been using SuiteLets as a poor-mans REST api for a couple years now.  It started as a way to integrate where SuiteTalk didn't support a record or operation.  Another GREAT benefit was not having to juggle credentials and worry about asynchronous access with the same credentials.

When I read about the RESTful support in the new version I thought "Cool, I can do this in a supported way now" but then I realized you still need to pass credentials.   Of course I understand that there are times when this is a GOOD thing but there are so many operations that don't warrant authenticated access (pulling inventory levels for a eCommerce integration).