I carry a Benchmade ATS-34, one of 1000 preproduction knives developed by Elishewitz. I don't consider it a "back-up" to my Kimber, instead it's an "incremental response" to a threat. I've taken two knife related defense courses, and it affords me the ability of addressing the threat in stages. There are times where i can not carry my pistol (i.e. I travel for business....some states are not as progressive as others), and I feel comfortable with just the Benchmade. IMHO, having a knife (or gun) doesn't mean that you are qualified to use it to protect yourself or others. Find a good course, and take it.......aagain my opinion only.