I bought the premium version of WATS this week after contacting the developer with questions first and testing the free version with my theme.
I ran into a couple of problems with conflicting site settings and had some requests and questions, and the service was incredibly fast and responsive. I can't see how the developer could have worked on anything else because he spent so much time helping me. All of my issues and questions were resolved, and my clients and I are using the system successfully. This is truly the best service I have ever received with any plugin, theme, or any other WP extension, and I love the features. I was previously using osTicket, and I'm so glad to be rid of it!
There are a couple of features that I would like to see in the next release, and the developer was receptive to my suggestions (such as including the name and ticket title in the notification email).
By the way, this plugin works with Pagelines Platform Pro (themes).