I think moving heads are just overkill for your typical wedding. All we are trying to do is illuminate the dance floor. A simple scanner or two and a centerpiece lighting effect (along with wash) is all you need, imo. On occasion, I will bring my Vue III and point it on the ceiling directly over the dance floor.
Actually, I have an alterior motive. I can illuminate the dance floor with colorstrips. While I like the effect of moving heads what I'm really after is to be able to use them to do a more dramatic, spotlight effect for the grand entrance, then re-spotlight the couple on the dance floor. When I pitched that concept past my fav planner the other night, you should've seen her eyes light up. I do appreciate your perspective on the scanners but do you really think they offer anything different than my tri-phase does now? I'm getting blow-back from a few brides as of late that they don't like the little dots all over the dance floor.