the 6000 has 6 levels of velocity switching available in the sound edit - you could put 6 different voices in if you wanted, and play a different voice depending on how hard you hit the keys.

the 3000 had dynamic accompaniment. this was a half fill which appeared in the backing if you played the left hand stronger, or the right hand stronger and/or quicker.

There were 2? patterns which alternated, and with the touch setting suited to you would come out of the blue and really enhance the style musically and break up the backing monotony. I liked it a lot, but they got rid of it in the 5000 because many owners never understood it, and claimed that nothing happened because they did not play well enough to trigger it. Shame.

I want it back in the composer (it only worked on the presets) fully programmable. It would be a great feature.