Vocalizers:
Roland G70
Korg(only the TC Helicon)
Ketron ( Good but quirky )
Yamaha doesn't qualify for this category & needs to totaly replace the unit in their KB's period!
Styles:
Very Useable, Smooth fills/breaks/generic & repetitive:
Yamaha
Punchy/live Sound:
Ketron/Korg/Roland
Swing/Latin:
Yamaha/Korg (swing) Ketron/Korg Latin
Sounds:
They all have terrific engines now...
each with different strengths & nuances depending on how you play them.
OS:
Roland Touch screen/makeup tools
Yamaha
Newer Korgs
Ketron tie with Korg once you get the idea on how they work.