Scott although I only auditioned the PAS the other day & I'll be buying one next week, I personally didnt hear a big difference when I played different pianos either solo or layered w/styles in arranger mode. It actually sounded better and so much more clearer and crisp then my current system even though its Mono.....that was one of my concerns also......but this system is not like a conventional sound system that we are used too. Uncle Dave has told me this from the start but until you approach this with a new knowlege in a BOSE Pas mindset you start to realize whats happening......Have you watched the PAS Videos DEMOS? As far as tweaking GM Piano sounds I will let Gary D, U Dave, Eddie S, chime in with their thoughts on the subject ok?