I'm sorry, I still find myself after all these years catogorizing my keyboards as Arrangers, Digital Pianos and Pro models. I then explain to customers that there are models in all three catagories a pro will play. A Yamaha Motif, Korg Triton, etc. are usually found on stage in concert situations and thus my calling it a "pro" keyboard. Please excuse my poor choice of words.
George Kaye
Kaye's Music Scene
Reseda, California