In my part of the U.S. I've always been fortunate in being able to shop at stores that have knowledgeable sales persons. The local music store no longer carries high end keyboards, mainly because of buying programs dictated by manufacturers. However, the owner and service persons know keyboards and operating systems better than most folks.

I agree with much of what Diki said--trust your instincts and judgement. The kids working at GC are mainly high-school and college age and what they know about arranger keyboards and synths can be written on the head of a pin and have room left to write a small manuscript.

I also suggest traveling to hear other performers using various arrangers. I've personally traveled more than 20,000 miles during the past decade to hear various arrangers and sound systems. The added benefit is you get to meet up with a lot of very talented individuals who frequent the Synthzone and other music forums. Lots of very knowledgeable individuals here who are usually more than willing to lend a hand.

Good luck on your search,

Gary