Thanks for your input. It seems that polyphony is something that even the sales reps of these digital pianos don't even understand. Most can't explain it, but I've been told by some that Kurzweil has a patented technology on how the sounds of their piano keys were recorded and that most, if not all, keys struck use only 1 note of polyphony per key. Whereas with Yamaha's sounds most keys take up 2 to 3 notes of polyphony with each strike. I've also been told that Kurzweil's orchestral sounds are supposed to be the most realistic in what the real instruments are capable of doing. In other words, if it's impossible to play an arpeggio on a flute for example, then you can't play it on the Mark 12 with the flute sounds. Anyway, I've had to depend on info I get from various sales reps since I haven't found any forums on the web that discuss digital piano "home products", which is what I want. I understand that most people on this forum are into portables, which I considered at first until I realized I'd have to add a speaker system, bench, stand, and pedals. Plus I like the auto accompaniment for personal enjoyment. Thanks again for your help.