I, like a lot of guys, have carried a pocket knife since I was in about the sixth grade, but have recently developed an interest in higher quality knives for possible self defense carry. I would actually hate to have to use a knife instead of my glock in a self defense situation, but if I happen to be in one of those places where I cannot carry a gun, and my knife is a last resort, I want a good one. I have had no formal training in self defense with a knife, except what I have read in books. Unfortunately I do not have the money for such training as of yet. One day maybe. I do believe, however, having one would be better than nothing at all. Anyhow, enough with my rambling and I will get to my question. I am considering the Benchmade blackbox rift, stryker, or Presidio. Maybe even the Griptilian. I have a mini grip as an edc, but might want the larger one. All of these fit my hand fine, and I am just curious if any one would be better suited as a dedicated true self defense knife than the other? Does one offer any specific advantage over the others? Also noticed the Presidio comes in an "ultra" model which is in 440c versus 154cm or D2. It is considerably cheaper. Do you believe the 440c steel is fine, or are the others steels gonna be that much better to justify the extra expense? If I go with the Presidio, I am leaning toward the "ultra" model. Any opinions would be appreciated, since like I said I am pretty new to the more expensive knives. Just trying to learn. Thanks for any input.