I must admit, I've played the acoustic piano for over 20 years now... I've taken a few years of lessons and theory, but mostly learnt by ear. I kind of see Scott's point in that the music assist in front of an audience would feel like 'faking it' for me too. Maybe this is just because I learned to play on the acoustic? Who knows.
All I know is I can't see and hear musician's from a non-musician's perspective. Sometimes I really wish I could! I know one thing for certain, if a member of my audience during a performance came over and realised I could press any key and it automatically was in the correct pitch, I'd probably melt off the stage out of total embarrassment! It'd be like a Milli Vanilli moment or something...
Carrie