Faking is never good.
It doesn't become better if you use the word "playbacking" for it, but the reasons you want to do that are different. If you are recording a videoclip fi your "playbacking" has a sensible purpose - if you pretend playing while you let the keyboard play a midifile without any contribution to it (like doing a great dance ) I would call it "faking".
If you use a midifile and still play along with it - for instance on another keyboard - you are also performing.
There are performances who interact with midifiles - changing the result with realtime actions on stage. That is performing too!
But if you play a midifile and PRETEND you are playing... I would call that faking, even when you made the midifile yourself.

If I play Love Boat I use multipads to add to my playing because I cannot play a countermelody at the same time as I do the main melody. But I am still performing because I play the main melody. And it is even risky, because if I press the wrong padbutton (or my timing is wrong) I am in a lot of trouble. (I use all 4 pads for the countermelody)
of course I programmed the multipads, but people think it is part of the style.
Of course some people think I programmed the style as well ..... I wish I did!!

[This message has been edited by drdalet (edited 08-14-2006).]