I have always had to open carry because I'm not yet old enough for a CC permit and I am not yet old enough to purchase a handgun from a dealer. There have been times where being concealed would have been nice, but I fail to see much of the defensive bonus of having a gun hidden that takes additional time to take out. I remember the element of surprise being an offensive tactic used to overwhelm your target. Also, if carrying a gun is meant to keep you safer and your gun is well hidden, then how does that deter crime? To a criminal, you look just like everybody else and they could target anyone on that block thinking that nobody has the means to stop them. If you open carry, then the criminal plainly sees that you are armed and that trying anything would be a bad call. The visible gun is a kind of deterrent and definitely raises criminal awareness that their potential victims could very well be hard targets. In a way, it sends a grim message. I am very aware that everything has its drawbacks and the tactical penalties to open carry are that you may very well end up being the first target or that someone who is desperate may accost you for your gun. No system is perfect and every style has its unique holes. These can be addressed by paying more attention to your surroundings and having a hidden backup weapon. Openly carrying raises firearms awareness in society and is a way of doing good PR work for gun rights by demonstrating that you are a normal, responsible, sane person who just decides that carrying a gun is their best option. If the gun is hidden, then how do you raise positive awareness of RKBA? Gun rights will not improve unless the public and the politicians are strongly convinced that guns are normal and beneficial to society.
mortablunt, I think I agree with everything you've said here, but I still prefer to carry concealed. (Not that I have any choice anyway in South Carolina, one of only a handful of states to completely ban OC unless on private property.) Even if I had the choice, I would almost always carry concealed anyway. Yes, OC can be good PR for gun rights, but that's not my primary reason for carrying. Same thing for deterrence. I would like the freedom to choose between OC or CC since there may be some circumstances in which OC would be more appropriate, and as a free citizen I should have option. But to be honest, PR and deterrence are probably the strongest reasons I would have for OC, and I need a little more than that. Just my personal preference though, and I don't judge others for their preferences.
The main deterrent effect for CC is that criminals KNOW some people carry, but they almost never know WHO we are. Violent crime has even decreased in D.C and Chicago over the past couple years, and those places still don't have THAT many more weapons than before SCOTUS took an interest in their restrictive gun laws. Also, the issue for those places isn't even CC or OC, but just owning operable weapons to be kept at home for self dfense, and yet crime is still decreasing. The point is, it doesn't take that many legal weapons in society to have a positive effect. See
http://www.foxnews.com/opinion/2011/09/30/media-silence-is-deafening-about-important-gun-news/ for more on falling crime rates in Chicago and Washington, D.C.
It's true that there is no "defensive bonus" in the additional time needed to draw from CC, but I'm not a gunfighter; I'm a citizen willing to defend myself and others with deadly force if it should come to it. It's the last resort for when only deadly force can prevent serious harm to the innocent. While it does take a little longer to draw from concealed, you can become pretty good at it with practice--SAFE PRACTICE. If you're aware of your situation, drawing from concealed should be possible in time to counter the threat.
But ultimately, all of that just leads me to what I consider the most important factors regarding CC vs. OC: 1) WHY do I carry at all? and 2) Whatever my choice, can I do it properly every day? Fundamentally, CC just answers these questions better than OC.
(Besides, as noted above, OC is still illegal in South Carolina, but that's a topic for another thread.)