I explained in a post yesterday where the Mega voices are located in the Guitar bank of sounds and that they can be played if you wish to but that for most players it would be very difficult because of all the layers of different guitar type effects being used to make them sound so realistic. I also explained how Yamaha used the samples from these mega voices on other sounds which are intended for you to play from the keyboard.
George Kaye
Kaye's Music Scene
Reseda, California