Having carried a sidearm professionally since 1972, on a daily basis, and having been a professional firearms instructor full time for a major LE agency, I say without a doubt that if you decide to carry a defensive sidearm without a round in the chamber, you should not even consider carrying. You are wasting your time and money. Just get a good set of track shoes and run.... in a bad situation. A weapon like the Rohrbaugh carried in a pocket or inside your waistband will not be fast to deploy to start with. It's main advantage is stealth and surprise. IF you add racking the slide into the equation at a time when you are in a hurry the advantage goes to the threat. Add to that, the fact that a very likely occurance that can happen is to short cycle the slide leaving you with a sound and no round, which is common for people who are both hurried and having a high adrenaline dump during crisis.
This is a bit reminiscent of the old military rules which called for soldiers in combat to carry 1911A1's with a 7 round magazine and none in the chamber and when needed to withdraw the weapon from the old flap holster and rack the slide. Even today there are those who are afraid of a 1911 series having a mind of it's own and so they fail to carry with a round in the chamber. That is faulty logic and is in part a product of a litigious society and in part a product of a lack of training, practice, and confidence. If you have the training and practice and are still asking that question, keep working on it until the confidence develops. Then you will know the answer to the question.