My folding knives are for utility use in the primary role. I use them a lot! I work in EMS so they do get a work-out! Therefore, I find the combi blades to be more useful and practical.
All my knives are strong and bombproof work horses such as Benchmade, Emerson, SOG and similar brands, so any of them will work very well in a self defense role.
I'm not a knife fighter, but I can, fight with a knife!
My fighting style is a universal method whether you are unarmed engaged in hand-to-hand, or whether you have a knife or club in your hand.
The techniques and the strikes are the same and are very fluid, targeted and very devastating! If I don't hit the subject with the knife, it's not an issue. If the knife hits the attacker, it's merely because it was there when I landed the blow.
I'm not focused on using the weapon per say... I'm focused on striking specific targets on the body. If I happen to have a knife in my hand and that is what connects, it's just going to be that much more devastating.
Again, I'm not a knife fighter, but I can fight with a knife.