Just started using postman myself. This is the first I have heard of PAW.
In terms of actual features, I can't live without 'dynamic values' - being able to copy response body values (almost like a pointer) and paste into the header of another request.
http://i.imgur.com/aY8A0NJ.png
It means that things like auth headers and 'current user ID' are always in sync and current.
We use the collections as both day-to-day development tools, as well as API documentation and a quick test layer.
Kudos to the Postman team!