>>since it's for a demo where it will only be played on a few flat screens would you bother?
Your question really isn't about audio; it's about work ethic. My personal philosophy is; 'If it's worth doing, it's worth doing right.'
If it is a demo that is associated with my name I would want it to be the best it could be.
Some people may wonder if you aren't willing to take the time to clean up the audio what else aren't you willing to do?