As an example: I had posted recently about an incident in a North Carolina Walmart where a customer openly carrying a pistol had said pistol stolen ... from off his person! Fortunately, the thief apparently was only interested in the taking the handgun, and no one (yet) has been injured as a result of the theft. However, the incident prompted a short article at Bearing Arms urging gun owners to carry concealed. That article, in turn, gave rise to a scathing critique (and defense of open carry) by Herschel Smith at The Captain's Journal. After reading these and other articles on the topic, and reflecting on the practice, I decided to inject my own 2 cents into the discussion and discuss the pros and cons of open carry versus concealed carry.
Open Carry: Pros and Cons
The primary advantage of open carry is ease of access. You don't have to dig for the firearm because it is not in a pocket, under a shirt or jacket, or tucked under the cuff of your slacks in an ankle holster. The advantage of this mode of carry is even more obvious in cold weather when you would be wearing a buttoned or zipped coat. While it is not difficult to pull up the bottom edge of a t-shirt to grasp the butt of your pistol, it can be difficult or impossible to do the same with a winter coat. Drawing is (in theory) easier and more sure because clothing generally will not hamper the draw stroke. This (again, in theory) allows for a faster draw.
Another advantage of open carry is that it can allow for carrying a larger handgun, such as a full-size service revolver or pistol. (Que the song, "Big Iron"). Basically, this all comes down to fact that the handgun does not need to be small enough to easily conceal under clothing or in a pocket. This may be an important consideration if you think you will need to deploy considerable firepower, be it better one-shot-stop capability (like from a .44 Magnum) or volume of fire (like a 17-round 9 mm). You can see again that colder weather favors open carry for the reason that you will want a handgun that can effectively penetrate winter clothing.
The final advantage often touted for open carry is that it will (again, in theory) deter potential criminals. Frankly, I believe that this advantage is somewhat dubious. Yes, if a criminal sees the firearm where one was not expected, it may deter him from committing a crime. On the other hand, the firearm may be what attracts the criminals. I started out this post by noting an incident where an openly carried pistol was stolen. Unfortunately, while not common, this is not an isolated incident. Massad Ayoob has noted incidents of police officers being waylayed so that some criminal could steal their weapon. And just a quick Google search turned up a few more instances from this past fall on the first page of my search results ("Off-duty Cleveland police officer attacked, gun stolen while working security at Taco Bell"; "NYPD Officer Jumped on Street by 4 Men Who Steal His Gun: Officials"; and "Gang member took cop’s gun, used it to steal car in Long Beach, police say"). I'm sure that I could have easily found more. While it is not clear that the Taco Bell incident was initiated for the purpose of stealing the firearm, the latter two incidents clearly where incidents where the officer was specifically targeted because the criminals wanted his or her firearm.
That segues into what I consider to be the primary disadvantage of open-carry: loss of operational security (op-sec) and the fact that it draws unwanted attention. It is possible to open-carry discreetly: I've removed an outer jacket at family events, thus exposing my formally concealed carry pistol, and not had anyone notice. Mostly, this has to do with the firearm being carried so that it is obscured by the arm, and the color and size of the weapon and holster not sticking out. Grays and blacks seem to do a particularly good job of blending in and not attracting the eye. But by open carrying, you make it very likely that someone will see the weapon. This can result in a criminal specifically targeting you to steal the weapon or making a fuss about the weapon. (See "Open Carry Part II: The Case Against"). It also advertises the fact that you own firearms, and someone might follow you to see where you live to plan a later burglary. But, most importantly, it reduces your options should you be tangentially caught up in a crime, and immediately elevates the possible force.
In his article cited above, Herschel Smith proposes that the speed advantage to open carry would be invaluable in a hold-up, such as at a convenience store. However, unless you were the specific target of the criminal, I would suggest that it elevates your risk. First of all, if the firearm is noticed, it forces you into playing a role in the event where you otherwise may have simply remained a bystander. Second, it heightens the tension of the situation, where it is more likely that lethal force may have to be used. Smith, for instance, imagines an situation where lethal force is needed to stop the criminal from shooting someone during a robbery. However, the more common scenario is that the robber(s) enters the store, demands money from the cashier, and hastily leaves. I, personally, would like to have the option to intervene rather than being forced to intervene.
And this ties into the second problematic issue of open carry, which is that because the weapon is openly carried, a thief or attacker may specifically target the weapon and try to take it. Thus, you have a greater need for an effective retention holster, not to just keep the weapon from falling out as you move around, but to prevent someone from purposefully removing the weapon from the holster. There are many different types of retention systems and levels of retention (see "What cops need to know about 'levels' of holster retention"). I have a holster for a service revolver that not only has a thumb-break strap, but is stitched up in such a way behind the trigger guard that the firearm cannot be pulled or inserted from a rearward or straight upward angle. I would consider this the minimum for an open carry pistol. Certainly the passive retention offered by most Kydex style holsters, or a simple retention strap such as on a holster used by sportsman, is insufficient for open carry in public. On the other hand, if it is harder for someone to snatch a weapon from a holster, it necessarily becomes harder for you to draw the weapon as well. An extreme example of this are the holsters that use a flap to cover and protect a handgun. Thus my comment that open carry is, in theory, faster for the draw. In practice, you holster and its location can significantly slow a draw.
Concealed Carry: Pros and Cons
The advantages and disadvantages of concealed carry are almost the opposite of open carry: a generally slower or awkward draw to clear clothing or jackets, typically a smaller weapon to allow concealed carry, but that the weapon is not displayed for all the world to see. Although most concealed carriers can get away with a holster with a low retention level, it is important to remember that in a physical tussle it will quickly become apparent to your opponent that you have a firearm. Thus, you still need to learn retention techniques and have a holster strong enough not to be torn loose or allow the handgun to come out.
Another disadvantage, in my mind, is that, realistically, concealed carry generally requires different modes of carry, and perhaps even different weapons. For instance, on some occasions you can carry in a belt holster of some sort under a loose shirt; other occasions may allow a bigger weapon or more comfortable holster under a loose jacket; and yet other occasions may dictate carrying in a pocket or a belt pouch or purse. Conversely, open carry generally allows a consistent mode of carry.
Obviously, if you want to make a statement by open carry or to exercise your right to open carry, you should. But I believe that concealed carry offers significant advantages for the person carrying a handgun for self-defense. Where open carry excels is in the forest and field, where a larger weapon is desired, or in cold weather where a concealed weapon may be extremely slow to reach.