I suggest checking out the demos The grand piano sounds GREAT! Also they even added scat voices to the list. They're not too bad either. The breathy alto may throw people off a bit, it sounds like there is some distortion in the sample (even at high res.) What impresses me is that Casio added newer better quality samples (including nicer sounding drum kits), doubled the user sample memory, touched up the styles, and didn't jack the price up by one penny.

Squeak