I suppose it'd be as good as anything else... but that's just the point.
How do I put this without being rude?
as Heinlein eloquently put it "If carrying a gun makes you feel 10 feet tall... let your sister carry the gun."
What this means is a couple things:
#1 if you are a civilian your primary defense should be hand-to-hand, not a weapon - they are for when things get out of control.
#2 don't carry it if you don't know how to really use it
You haven't been clear on your occupation, experience, or what on earth you think you need to carry a 5 1/2 incher for "protection only" so i'm going to assume that you are just getting acquainted with the idea of personal defense, please forgive me if this is not the case.
The way I, personally operate is thus: I carry knives as tools - pretty simple. Sometimes they are belt knives, folders, neck knives, whatever, I carry these because sometimes I need to cut things, and because I enjoy collecting and carrying knives. I view none of my knives as an inherent weapon because that's not what I carry them for. When I need a personal defense solution, my hand-to-hand comes into play. The ONLY time I would think of pulling my knife on someone would be if things had escalated that much - either my attacker is extremely aggressive and determined, or has a weapon of his own. Believe me when I say that the police won't see it your way if you pull out your knife for small squabbles.
That said I don't have a problem with people carrying weapons for self-defense, provided they consider it a last measure, are properly trained in that weapons use (can be self-trained, just make sure you know your way around it), and are legal for carrying that particular weapon. I believe that America would be a better place if everyone could carry a concealed firearm, but that doesn't mean I condone breaking laws towards that end. I'm not sure how it works in Texas, but make sure if you carry this knife that it is legal to do so in whatever fashion you intend.
So the bottom-line recommendation after all this is: take some hand-to-hand defense classes - your hands can go to work faster than any weapon can in a pinch. Once you know how to protect yourself WITHOUT a weapon, if you still feel you need one and can legally carry it, go for it, just keep it as a last resort.
Sorry if I rambled a bit too much, I just wanted to make my opinions clear.
