Rattley: VERY well Stated.
I'd like to add my comments to this same subject, but more specifically in regards to acoustic piano playing.

No matter how you slice (or more fittingly, pound) it, absolutely no 'arranger' keyboard's keys ever produced (Yamaha, Korg, Technics, Roland, Ketron, GEM, etc) even comes close to feeling like or responding to the way a fully weighted action with full sized keys on a acoustic piano's does. . . . period !

Even so called weighted action digital pianos don't feel like real pianos. "Touch Sensitivity" and "Weighted Action" is not the same thing as the sophisticated inner mechanism, or "action", of an acoustic piano. Digital pianos merely simulate the touch of pianos. They don't provide the same feedback or responsiveness to your playing, so your performance range is limited.

I realized long ago that arranger keyboards are primarily targeted to the home hobbyist and not the traditional keyboard pro musician. The unique advantage of the arranger keyboard for the professional solo performing keyboard musician though is that it offers a complete keyboard with a complete backup band in a self contained lightweight 'portable' (under 30 lb) package. I've noticed that most arranger keyboard players don't come from a traditional piano playing background, but more often from an accordion or organ playing background. Both the accordion & organ are instruments particularly suited to solo performance because they allow you to emulate many different types of sounds (instruments), via registers. The arranger keyboard being just the next giant step in this evolvement.

As far as the arranger key size issue goes, one possible reason Yamaha chose the slightly narrower keys may be to help keep the overall length (size) of the keyboard down, which also affords convenient (within easy arms reach) access to all its arranger function buttons. Some of you may laugh off the Yamaha keyboards as just toys , but it's 100% professional to me because I'm able to make a living with it.

When playing an acoustic piano (especially a Grand), it's a whole "different" playing experience than with auto-accompaniment arranger keyboard playing so both require a very different playing technique & playing approach. Once one accepts the fact that an arranger is no more similar to a piano than an accordion is to the organ, it will become a lot easier to adapt to each and enjoy playing them for the unique abilities each has to offer, and this includes the Yamaha arrangers, of course.

Scott