Altering the sliders to change volumes is the only natural way to do this on the fly hence why sliders are used on most mixing consoles but using the sliders to change sounds is plain stupid. You can see in the youtube clip that the guy at times has to take both hands off the keyboard at the same time to alter settings on the fly !!! And numerous times he has had to go back and adjust the settings in mid flow because he did not grab the correct slider first time or did not slide it far enough or too far to eliminate one sound so that it did not double up with the new right hand sound. If that is intentional then thats why a true arranger in terms of live performance cant be beaten because ergomically it is configured specifically for live play.