I will disagree about any tactical advantage of OC as opposed to CCW. To a CCW, concealment is the single most important tactical advantage that a permit holder (or off duty or plain clothed cop) has. It provides the CCW with the advantage of surprise, as well as gun retention - if a crook doesn't know someone is armed, then he's likely not going to attack someone to get their gun. He's also going to be caught off guard when the weak appearing intended victim shows him a muzzle. Pretty much all law enforcement agencies with any kind of training emphasis on officer survival skills issue or mandate the use of a level 2 or 3 holster to help prevent against gun grabs. The open display of a firearm has not stopped attacks on police officers. Some officers who have been attacked were tactically sound and possessed superior firearms skills. The uniform was as much a target as a deterrence. Criminals are not all stupid, and sometimes more in tune with their animal instinct survival skills than cops and law abiding citizens. Getting the drop on a police officer or OC is certainly not outside of their comprehension. I've talked to plain clothed and retired cops still carrying, and they've told me about how criminals expecting to target sheep were quite surprised and detoured by the sudden introduction of a concealed handgun. On the other hand, how many practitioners of OC have the training and experience to carry their weapon in a manner that gives a crook the impression that they're not dealing with an inexperienced wannabe? How about the ones whose states/cities allow only for unloaded OC? Imagine the image presented to a criminal with a piece stuffed in his pants under his shirt of a guy with an empty Glock in a cheap, flimsy holster prancing around in public? Now, if I was in a gun store to commit a crime and observed all of the employees had OC pistols strapped on, I might be inclined to go somewhere else. Still, such a show of force has not prevented active shooter attacks at police stations around the country. I've got to wonder about the real agenda of some of the OC supporters.
While slightly off the subject, the news in my area reported a couple of weeks ago about gun thefts from vehicles in the metro. The report said that a significant number of the vehicles from which firearms were stolen were displaying NRA stickers. I am NRA Life, but why advertise, especially if you're going to leave your gun in the car? If you have to leave a gun in a vehicle, take measures to at least make them work for it. Police cars, even those with secure weapons racks are not immune from being targeted.
i got the "do you really have to have that" wife...she despises my toys. i despise her demands for the dishes to get washed, but i keep it to myself 
