I use Postman all the time, and I love it!
However, I work with both REST and SOAP services and I find that I have to keep leaving Postman to use another tool (like the Postman-wannabe, Boomerang, in Chrome) to generate the appropriate requests from a WSDL, so I can copy & paste the resulting XML into Postman for ongoing testing.
I know that SOAP is old school, but some of us have to keep integrating with it, and I expect that will continue to be the case for way too long to come! I wish Postman could read WSDLs, too!