Caporegime
The STX is supposed to be amazing for top end headphones and extremely good for music. The SBZ is lower quality but has CMSS3D, which is much better than dolby digital (which I used to use) if you want to use either.
I just use it plain to be honest, don't mess with EQ or anything, just unadulterated Stereo.
I'm confused though why this is an issue. The higher end motherboard sound chips are mostly just standard ones but isolated, it's an important point if you're buying is influenced by the sound.
It's not an issue, it's just further misrepresentation which no one ever bothers to address.
I'd say the same if it was someone bigging up any other board.