Whilst comfort and clarity are clearly very important, headsets are also meant to be protective equipment. It seems strange that they are not regulated by any industry standard testing and that they do not have to display their rating at providing hearing protection. Especially when you consider that companies issuing them have to conform to so much health and safety at work legislation.
A simple graph showing attenuation against frequency and an indication of aircraft category suitability would clear up any confusion when comparing different models and makes of headsets.