I also think Yamaha is in a good position with arranger keyboards and isn't forced to release new models in a fast pace. Roland as a competitor has (sadly) become quite insignificant in this segment, Korg is the only important competitor. It's different with synthesizers however: there's not only more competiton from Roland and Korg, but also by computers as the younger clientele risks to completely change over to software libraries and iPads etc. even for live use...