I see what Chas "Charles, Charlie" is trying to say alright.

Arrangers do not necessarily make you a polished keyboardist because the accompaniment detracts from correctly playing the keys and therefore keeps you from advancing in your keyboard playing skills. Advancing in proper technique key playing that is.

But I think you are forgetting Chas "Charles, Charlie - Hey you!!"

lol >> sorry Chas I couldn't resist,

you are forgetting that most OMB players don't play in accompaniment mode 24/7, at least most of them anyway, so there are opportunities for arranger players to practice up on their Piano/Organ, etc. skills when the ACMP is off. Like Tony said, when he plays in a band setting he plays in Piano mode. As do I as well. In fact there is no way an arranger keyboard could/should be used in a real band setting beyond maybe doing so on an occassional basis with a Bass player and Drummer perhaps. When I am playing with a band I always turn accompaniment off. If I didn't sharp objects would be flying towards me in rapid succession.

I play my Tyros "oftentimes" in my home studio without any Style accompaniment and in fact OMB playing for me is maybe only 30% of my total playing experience with arranger keyboards. And I agree wholeheartedly that most professionals (big time artists) use an arranger only for a sketch pad or for making song arrangements in the studio or on the road and wouldn't be caught dead on stage with an arranger and especially with an arranger in accompaniment mode.

Although with the advancements in keyboard technology and with soon coming breakthroughs in making arrangers sound more natural and life like to what a real band in a real band setting sounds like i.e. not mechanical or artificially canned looped based sounding so much, then things could drastically change and we might even see these big names playing an arranger (although I don't think they will be called arrangers but something else by then) - on stage in a live setting and with other band members playing along on their respective instruments. Maybe not in our lifetime but in my opinion it could be in our lifetime. I think the Ketron Audya is a trend setting step in that direction right now. And I'm sure Yamaha, Korg, and Roland will follow in that direction as well. If not, they risk being left behind the technological curve in my opinion.
It's a great day to be a keyboardist, and "especially" of the OMB kind in my opinion.

And the reason I say that is because there are going to be things done with arranger keyboards in the near future technology wise that are most likely gonna blow our minds! No, it won't make a person play more skillfully in a correct technical fashion per se (he or she will need to do that themselves in Piano Mode

) but from a technology standpoint of what these new arrangers will be able to do musically and sonically will be astounding to say the least. And all I can say is bring it on!!
Best,
Mike