I am by no means a "knife fighting expert," but the Karambit or whatever seems a little gimmicky.
My Benchmade Griptillian can open and close one handed with the thumb studs, and it's not spring assisted. So can my SOG Visionary, which is made of a lot better steel than what the Karambit is for about the same price.
Korey - Shamrock Armory
Glaine ár gcroí, Neart ár ngéag, Beart de réir ár mbriathar.
Purity of heart, strength of arms, and truth in words.