The reason I have carried my Rat Trap for all these years is that it is light and carries well. Before that, I carried a Cold Steel Voyager. Whatever knife you have on you when a "survival" situation occurs is a survival knife, IMO. So a knife like the HEST that carries light seems realistic to me. Your personal "Doomsday" is the only one you might be able to do anything about anyway. Not going to stop a comet or a flood with a pocket knife.