Ketrons and especially AUDYA sound fuller, more "live", and generally cut through your PA like NO OTHER ARRANGER.
I have tried Korgs, Rolands, and KEtron, except Yammy, but i know what the result would be with Yamaha
as far as Stacato Heaven, NO OTHER keyboard can reproduce it, not even the latest Roland keyboards,
the D-50 is a classic, and that is why i will keep mine forever...