I really don't see it as useful unless you are facing some sort of eotwawki situation (which is extremely unlikely), there are just too many restrictions and stereotypes for it to work. Have someone kicking your doors down? Better convince the robbers to wait while you take your firearm out of the safe. I recall on the news some guy had vandals firebombing his house, he fired warning shot in the air. The cops came, didn't even bother looking for the vandals, just arrested and charged him for unsafe storing of firearm.