I think I do prefer a bit of positive retention for OC. I guess my thought is that some retention may protect my sorry butt in case of a la-la-la moment of lacking situational awareness giving me a brief reality check and time to overcome the situation. When I OC around any sort of crowd in non-retention holsters I find myself spending a lot more time thinking about the pistol, its position, etc. than I do with retention holsters. I don't mean just SA, but almost distracted by it. If I'm not around any significant crowds, 95% of my days, it doesn't matter either way.
So, long and short, if I'm OC and know I'm going to be around crowds, Christmas shopping, festival, labor day weekend White Sale my wife drags me to, I'm choosing a retention holster that day. To just go to work and stop at the store on the way home, it doesn't matter to me.