Glenn, the COVER feature is useful if you don't like the original instrument assignments of a SMF or style. The various covers will insert different instruments to give a completely different sound. It's nice when the original sounds need some tweeking but you don't have the time or talent to change them up, or maybe you just want a change...

The DC5 is a great instrument and many of its features carried over to the G70 and E80/60/50. The harmonizer and cover features set the Roland keyboards apart from the others.