I don't typically concern myself with how folks carry their firearms, but I do notice those that do carry. It's just part of my situational awareness particularly when I'm boxed in, like at a restaurant or some such place. However, there is one mode of carry that does irk me somewhat........ a horizontal, shoulder rig!!! I was at a restaurant once when a guy wearing a sport coat walked in. He sat with his back to me waiting for someone to join him. When his dinner date arrived, he stood, took off his coat and sat back down. He had some sort of badge on his belt and the aforementioned horizontal, shoulder rig.
When he sat down, again with his back to me, I was staring right down the barrel of his .45 ACP 1911. Now, thank goodness that he at least had the decency to carry a pistol with a manual safety in that type of rig, but still, I don't like to eat with a gun barrel pointed right at me. I don't care what kind of commando you think you are, I don't want to be anywhere near you when you're forced to draw from a rig like that - safety or no safety. Yes, it looks cool, at least on screen, but it's disconcerting for those around you. I moved, and kept an eye on him and his pistol's muzzle.