Did Yamaha also neglect to put a mono piano sample in the P250, like they did with the P120 and the P90. Ironically the P90 is marketed as a "stage piano"?
Maybe that's why I have yet to see a pro using the P250 on stage.
Running stereo piano samples into a mono sound system you will get a rather thin, edgy, attack only type sound.
I bet the P200 had a mono piano sample and that Chuck in the Rolling Stones and Elton John both could use on stage.