I personally would email the event host to tell him/her how displeased I was at this rule, in a effort to try to change it.
To answer your question, I despise them. I never will play somewheres that has bang kills in effect. I have been bang killed once, and it was complete bs to say the least. I was on the corner of a building, I had snuck up behind the entire enemy team and was on a really good streak with a huge edge over the team, and then this kid ran around the other corner and started yelling "BANG BANG" before he even saw me, and the best part is that he was at least 20 feet away from me, way out of the arms length bang bang engagement distance. I took my out, but I was not happy.
I think that the best alternative to the bang rule, is the much similar surrender rule. To surrender someone, you simply yell "surrender," and if they choose to surrender, they will comply and take their out. If they choose not too, then they have the option to turn around (assuming you snuck up on them) and shoot you, too which you may respond by shooting them as well. This rule is a lot of fun and I think makes sense as well. As I have never been frustrated when playing with this rule, in fact I have only had a lot fun.
That's my two cents on his topic.