Hate 'em, hate 'em, hate 'em. I do not want drums in my monitor. I want to hear them from the drums. I've used them twice in my life, and will never use them again. I couldn't hear the drums at all, nor could I communicate with the drummer when needed. If a soundman can't get a good onstage sound without them, then I'd be looking at a new soundman.
This. Jimmy is correct!