I agree that "reaching" or implying you're armed is a bad idea. If you can do that, usually you can get out of there or de-escalate some other way. If you end up needing the gun, you just lost what little surprise advantage you had...
Like I said, I've done it several times, and it worked without me having to draw. I was fully ready to draw AND shoot to kill. The would be perps just wizened up in time so I didn't have to. I agree there are some that wouldn't be intimidated by my being armed, I've seen them in action too (though not with me). Let me give some info:
1. Walking through a dark parking lot outside a restaurant. We had just come out, were getting near our car when a BG approached us holding a steak knife. I went for my gun (the reach) he dropped the knife and ran off. I still have the knife in my kitchen drawer.
2. Coming out of a bar at 12am (didn't have my gun this time, just pepper spray) again approached by individual/panhandler VERY quickly with obvious intent to head us off. He had a look of unmistakable malice on his face. Went for the pepper spray (the reach), he turned right around and walked off quickly the way he came.
3. Riding in a horse drawn carriage at night in San Antonio. I had rented it exclusively for just my wife and I. An individual with an obvious meth problem attempted to enter the carriage with us. Got right up to the carriage and put a hand on it to help himself into it. Went for the CCW again (the reach), he wised up and let go and walked away. Don't know what his intentions were, and I don't care. He had a fixed blade knife on his belt and he wasn't going to get a chance to use it.
Like I said, I was willing and was actually one step away from drawing my weapon and using it. The BGs were just smarter than they looked and left the situation before I had a chance to.