But are they successful in this? A lot of actions broadcast globally to a room, while others don't, and it's always seemed pretty arbitrary to me. Even if I suspect someone isn't watching me, I can't ever really take advantage of this because I can't recall if, say, taking out a grenade and pulling the pin on it is an action that the whole room sees or not. You could argue it's something you learn to pick up and intuit, but in three years I never have.
Cutting spam from busy rooms is also not something I ever want when it's IC stuff happening. Having a lot of scroll in a room already simulates a confusing/busy atmosphere where you're liable to miss things.
Mostly though, it's just confusing, and unnecessarily so. It never feels consistent that some rooms are busy and others aren't, but why do I have to use watch/address in this bar and not that one? It's arbitrary and not terribly easy to remember.
My experience with watch/address is almost entirely me forgetting to push my watch/address all macro and getting confused as to why the person I was looking at got on a motorcycle and rode away without me noticing, or having confused third parties hearing half of my conversation with someone else and assuming I'm speaking directly to them because they chose to watch me. I know it's been around forever and we're all used to it, but I just don't think it adds anything and it causes a lot of confusion.