Right Not Exercised is a Right Eventually Lost
I support and practice discretion, common sense and freedom-of-choice. Most days, I carry concealed because I'm doing business and prefer to be discrete. On other days when not doing business, I will occasionally Open Carry while in posession of my appropriate documentation for my State.
What I've found is that in most instances, most people don't even notice. They are in Condition White - i.e. not a clue. When I do open carry, I practice situational awareness and dress nicely so as to not upset the sheep. I might carry my coffee in my strong side hand so it's obvious to anyone who might get nervous that I'm not looking to be a threat. I've also trained in sidearm retention and combatives for good measure.
I do believe that Open Carry is not necessarily a tactical disadvantage. Open Carry does give us an opportunity from time to time to educate others that the legal carry of firearms is not a bad thing and we are not Bad Guys. Those that have noticed my sidearm have also noticed a nicely-dressed, well-behaved, peaceable courteous and friendly guy who's just going about his business. I've had a few occasions for nice conversations that seemed to have opened the minds of the other person. So overall, excercising the option has been a good thing. I've never had any crazies from the DSPRK (Democratic Socialist People's Republic of Californistan) hassle me -- but I did have the opportunity to alert them that Open Carry is legal in our state if the bearer has the correct documentation. Never had a 'Man With a G..G...G...G...GUN' police episode. Had coffee and conversation with a local LEO who mostly just discussed gun preferences, local ranges, IDPA etc. after ascertaining I had my 'blue card' with me. Nice guy, no hassle.
When I travel to Arizona, I see a lot of Open Carry - as the custom is well-entrenched and regularly applied by locals and others passing thru. When I travel to Utah, I occasionally see Open Carry there as I sometimes do in the state of Nevada. I believe that if one is going to exercise the option of Open Carry, he should remember he is an unofficial Second Amendment Ambassador and should conduct himself or herself with courtesy.
So bottom line: OC is an option. Use common sense. Carry concealed where you must, carry open where you can and if you feel like it's appropriate that particular day.