The argument really isn't entirely about whether you can make it out or not but also the ease of doing so. Why strain your eyes doing something on a SD TV that would be easier to me on a HD TV? Also all SD TV's aren't created equal. You seem like a reasonable intelligent person so I am sure you have tweaked your settings etc. to your optimal preference, but everyone's SD TV isn't the same. Your SD TV sounds like a flat screen, while some are not. I don't really understand arguing the benefits of SD vs HD as it would seem obvious. Is SD gaming possible? Yes. Is it optimal? No. The same goes for playing with or without headsets.
Me too. Its only a hearing advantage compared to someone without using DSS, obviously. It doesn't guarantee success nor do I see it as unfair. I use them because I want the best experience I can get. I don't deny it helps me hear enemy footsteps. Thats an advantage I've been using since WaW SnD. Soundwhore for life.