160-180 degrees is nothing. Most bars and smaller venues, hell even some large ones, have people everywhere. In front, left side. right side, behind the band etc... So running a stereo mix in a crowd like that is just plain silly. Especially when doing a live band. Most of the instrumentation can destroy the stereo mix too. Maybe you could have 2 drummers. One near stage left speaker and one on stage right. Each only playing half a kit. Stereo set up is only beneficial in near perfect scenarios. And when not in that perfect one it can actually ruin the sound to the audience.
I personally do run break music in stereo most of the time. But only when I'm in venues that don't have audience placement issues. When I play on the cruise ship (on my way there now) the speakers are spread out far enough that a stereo mix will lose half the sound to half the audience. The room is long left and right. It sounds better to the room mono. And a big FYI to you stereo only people, there a a lot more rooms that are not perfect than those that are. If you refuse to run mono when it's necessary than good for you, ignorance is bliss.
