Does anyone know what the story with EPOS is? As best I can figure out, they're a gaming (and corporate too, apparently) audio company formed by Demant, who had been partnering with Sennheiser. It looks like Sennheiser have sold their "gaming dept" and EPOS/Demant will be selling Sennheiser's existing gaming headsets under their own brand, and developing their own products too. The first of these is due to debut in October.
I know most here use headphones rather than headsets anyway, but I gather some of the Senn headsets were reasonably well thought of. Looks like the GSX will be an EPOS product from now on as well.