I got the orchestral ROM upgrade but haven't had time to install it yet, so can't comment on those sounds. It has some AWESOME sounds and I would be happy to use it as my main board anytime. The main reason was that it has exactly the same action as my main K2600 board in my home studio. I bought a PC2X as my practice keyboard to keep at work. Realize what you're willing to compromise.as unfortunately.that is the one common denominator that bridges all of these digital keyboards together. I actually obtain really nice results by using the two layered together.
I find that while the acoustic piano (triple strike) sample on the Kurzweil seems to be better tends to not resonate as well as the Yamaha.more like a spinet than a grand. I feel that Kurzweil has many 'truer' sounding acoustic instrument voices, along with better 'real-time' performance mapping ( modulation routings, aftertouch, etc.).
Despite subtle velocity switching issues (I say subtle because the velocity problem that certain individuals tend to complain about isn't apparent in actual performance usage), which incidentally occurs in all of these sample players.the S90 voices 'cut thru' better in the mix.
As an S90 & PC2r owner, I can tell you that my experience has yielded better onstage results with the S90.
