But I think there's a rebuttal to this. Put simply, here's my philosophical model:
A. Your demo reel is a compilation of all your best art, and anything sub-par should be removed.
B. By definition of a demo reel, it shows off your editing abilities.
C. Since the art of editing CANNOT be removed from your demo reel, it HAS to be polished into a beautiful "piece."
D. As numerous media shows (previews, music videos, video in general, etc...), an integral part of good editing is based around your ability to present audio dynamically, so that it goes hand in hand with your visuals.
E. Therefore, a demo reel should have dynamic visual and sound editing.
But of course, then it's worth exploring what good editing is. After all, in the same way that no sound is still technically better than bad sound or over-complicated sound. What I've discovered is that the point when music on my demo reel sucks is when it's clashing with animations that are already animated to sound. I predict that in an ideal world, my demo reel will be comprised entirely of clips that already have a built-in sound narrative, and therefore no new audio is needed.
And my render's done! So enough burning time.