The biggest advantage is the many ways that you can carry the little jewel. If you look carefully at what Front Sight offers, you can hook up what she calls a "bikini" sheath almost anywhere on your body. If you buy the mounting studs, it can be put almost anywhere, i.e. your clothing, strapped to your body, etc. You can deploy it in ways that don't telegraph body movements. Actually, it's about getting a 2-3 second edge. The fact of the matter is that most "engagements" can be settled quickly, if ruthless, decisive action is taken. I believe that a person can use one to defend ones self, but practice is necessary. Take a good hard look at the website, because, truthfully, almost all of your questions are answered there. Essentially, you have a small piece of SV-30 that fits over two fingers, and the mode of employment is very intuitive. Be aware that it is VERY sharp, and buying the practice blade is a real intelligent thing to do. Repeat after me, wicked, razor sharp. So, it's a cool thing to have, if you can deal with an unconventional blade that requires thought and practice. By the way, Front Sight is pretty cool to deal with, and her blades are really popular among self defense oriented folk. It's just that most folks can't deal with the idea of being in a deadly serious situation, and using an unconventional system to save their asses.