I never understood why an FBO wouldn't want to let you try something out.
Heck, you can go into almost any store, and try on clothes, which cost 50times less than some headsets.
Of course, if everyone got to try out a Stratus 50-D, then maybe nothing else would sell?
Problem is, I think a real trial is a 3hr or more xcountry flight. Not sure how many FBOs want to loan the things out for such a long time. I've seen larger shops have them on display you can try on, but I doubt you'd be able to take all the $500+ sets out for a trial all at once, switching between them, which is what is really needed. Maybe a test room, with simulated noise, or an intercom setup in a maintenance hanger, while they are running up an engine.