What I have just discovered is that until I started playing my Ketron SD7 at gigs my audiences really did not care or notice which keyboard I was playing. But they sure can tell a difference and have often said they prefer the over-all sound of the SD7 to my Tyros 4. I believe what they are hearing and feeling is the huge difference in the rhythm and bass sections in the styles of the SD7. Just sayin'.
Deane
Did I mention that I'm looking forward to the SD40?

The good drum samples and rhythmic arrangements make a noticeable difference, but Ketron also manages to make simple samples (e.g. one-layer trumpet sample) sound very appealing due to the use of naturally sampled vibrato. (That's why I prefer a conventionally sampled Ketron trumpet over a Roland SuperNatural trumpet.)