Some good stuff on monitoring in this thread, must admit I like to get it as quiet on stage as we can, within reason and limited by the drummer who isn't as easy to turn down, don't get me wrong it's still punchy on stage but we're not having a volume fight and we seem to be able to monitor the vocals quite well.
I went into a local gig we do quite often recently and there was a band on, I said to one of the locals, "bugger me Pete, these boys are loud"
he looked at me and said "you're as loud as this lot!" I had no idea, it doesn't sound it from were I am.