as for testing.
I wouldn't expect a phone rep to have the test specs sitting right in front of them. Nor would I expect them to know the data off the top of their head. They are hired as phone / sales people.
As for any competing product that claims that Dura/gunkote is inferior because of a lack of testing, feel free to post the test results of your product and be sure to mention the acredited lab that performed the tests.
I have used neither product, but I find dismising a product due to its inferior testing (which has not been shown), based on a single phone conversation, silly. Espically when the competing product just claims that the testing has been done. If so, just post a link to the report, I understand that if it has been done properly, the report should be quite lengthly, but the wonders of the internet make such miracles of information possible.
Technically, the supposed lack of testing could be hiding the fact that the Dura/Gunkote products to be superior