Vadim,

Of course, arrangers are also synths, but what I was referring to is certain kind of antagonism between synth players (musicians in a band) and arranger players (one-man-band musicians), where majority of musicians who play in bands consider arranger players as not really a musicians.

I doubt Bert produce styles, he is professional Yamaha demonstrator, and as such, he have lot's of work to do by demonstrating new Yamaha gear, while somebody else is creating styles for arrangers. Beside, this Tyros 2 presentation was the first time he demonstrated and arranger, before, he demoed synths only (Motif ES, Motif Rack, Motif XS, and MM6) although the later is some kind of cross-bred between synth and arranger.

Yamaha arrangers are usually demonstrated (at least in video form) by Michel Voncken, and he really do the job perfectly.