Bob is right. It basically comes down to how the source material was recorded. I've found that you you get more sonic value in the mono mode. As far as out board processing, it all works equally as well. I'm sure you can drum up an array of differing opinions, but it basically comes down to what sounds best. The fact remains though, most karaoke is not recorded in stero, that's why the multi-plex format lends itself so well to it. JMO.
