the piano sound from the kurzweil is very 'processed'. by 'processed' i mean it's not as crisp and clear cut in-your-face like yamaha or roland ones. i had a kurzweil me-1 and the piano sound was quite lacking in sustain and sounded rather woody. like, the piano was being mic-ed up and you're sitting listening to it in the audience or something. the sound didn't make me feel like i was playing a piano, felt more like i was listening to a piano being played. it sounds great in a mix, but for solo playing, i wouldn't use it.
but anyway, their rhodes is really nice. warm round tone with nice attack that's not too harsh. it's the only sound i liked on the kurzweil module.
and, kurzweil boards are quite pricey. and only 48 notes of polyphony! 8O (and a miserable 32 on the module)