Tony, as I said on an earlier thread, the Arranger Keyboard's biggest detractors and critics are usually players unable, unwilling, or too lazy to adapt to the playing style needed to bring the best out of the instrument.
Having done hundreds of clinics and demos, I have learned that many competent (and usually well seasoned, and perhaps stuck in their ways) keyboard/piano/organ players can't adapt very well to the system needed to play an arranger in "style" mode (which is the instrument's primary forte)...it's a combination of "dumbing down" whereas you have to play all chord types and inversions in a limited space, and "wisening up" in that you really have to know your chord voicings very well in order to play anything reasonably complex.
Plus there are creative arranger players just like there are creative organ/piano players...it's all how one uses the tools they have chosen to create with...a "Swiss Army Knife" in skilled hands can do far more than an ordinary pocket knife in equally competent hands.
Again, its hardly an instrument we should have to defend...it does what WE want...who could ask for anything more?
Yamaha Tyros4, Yamaha MS-60S Powered Monitors(2), Yamaha CS-01, Yamaha TQ-5, Yamaha PSR-S775.