Why fight for the right if we wont use it? It'll just get taken away again.
The only valid argument for concealed carry over OC is the "element of surprise".
Which when you weigh out all the factors isn't much in the grand scheme of things.
1. If your going to say that the criminal will shoot you first you might as well not carry at all for fear of being struck by lighting while having a block of steel on your hip. The odds look similar.
2. Ease of access, no snagging/fumbling, faster draw.
3. You can use any gun you'd like at that point. IE the one your most proficient with. (how many of us can truly say that we are as good with our subcompacts and our mouse guns compared to our full size?)
4. Comfort in general
5. The fact that you openly carry a gun DOES act as a deterrent to those about to commit a crime. Robbers don't want to commit murder, they want to be in and out. I would venture that given the opportunity, this type of reaction would be far more likely then "Oh, Ill just shoot that guy first!"
6. You can wear clothes that fit you and you don't need to keep your jacket on when its hotter than you anticipated. How good is your situation awareness when you're panting like a dog?
7. More mag capacity
8. More room to store mags as you may not have worn a mag on your belt when you CC'd.
9. Just because you wont NEED a retention holster doesn't mean you cant get one if you don't want to.
10. And it gives you a reason to go out and buy a bad-ass leather rig for your beautiful hand guns that you've up until recently been shamed to keep under clothing up until now
Or you could sacrifice all of that for the element of suprise... Which wont even come into play if you are the one being attacked. Remember you're attacker is watching you.