I have carried a SAK for my childhood, and then switched to a Leatherman. I find I use those tools as much as the blade. I carried a few flippers for a while because they were handy and I had this idea that "if I needed it to defend myself" it would be nice, but as stated above, it's not going to be worth a crap. I stopped carrying those because as I descended into this mindset of "self defense" even with things like the clinch, or the goofy ones you wear around your neck so you can be strangled easily, I realized my efforts were best utilized getting a tool I use 99% of the time. Otherwise, it's turning into Dwight Shrute with shivs, auto knives, and throwing stars. Carry a good blade for work, carry a pistol for self defense, and spend less time worrying about the .01% chance I'm getting shanked at Arlan's. If it's your time, it's your time.
That said, if I only used knives, I'd get an automatic or fixed blade because they are nice for one handed operation.
That said, if I only used knives, I'd get an automatic or fixed blade because they are nice for one handed operation.