Jeff - My first consideration was a defensive Khukuri, which of course implies concealed carry. Yvsa steered me toward the 12" blades, and I have a Sirupati and an AK. The Sirupati is much favored by the Martial Arts guys, as it is a fast blade. The AK, just by holding it, is a much more powerful blade. I don't think there is an ounce of difference in their weight.
When Bill Bagwell wrote for SOF, he bemoaned the fact that there were few who realized that a large Bowie could take off an opponent's hand. No one who has handled even a 12" AK would even think this a strange statement, applied to a Khuk. "Concealed carry" needs more consderation, as well as a flatter sheath, with a lining of very cut-resistant material. Both my brain cells are working on this as I type (which means one of them is asleep) but it is coming. Legality may rear its' ugly head in most areas. Here, our CCDW law allows concealed carry of "other than normal knives" - yep, wide open at this point, and so far uncontested. While the larger blades are more awsome, the little ones are still bigger than most seen on the street, and they don't lack in deterrent value. As a defensive knife, I'm sticking with the 12s, with a lean towards the AK. "Martial Arts" to the contrary, the Gorkhas interviewed about "style" said "Chop to head, chop to chest, cut across legs, all good". There is a 400-year-old lesson in K.I.S.S.