I don't know why but I still prefer the Yamaha nylon guitar, sax and piano in my psr s900, however when I compare the sounds one on one with the real instrument in a mp3 song (ie a jazz band), the Pa3x sounds are truly more realistic, thicker and have more posibilities to articulate them (joystic, ribbon). I still wonder how Yamaha handles those effects to make me prefer lower quality samples so much.