What the spyderco looks like (price found on the net $289.00, ouch)
http://www.youtube.com/watch?v=7CswZ6x6xHM
I have the Emerson Karambit with the black blade. Very fast in deployment due to the wave, very sharp, be careful with the thin point on the blade (used to cut, not to pry, yeah don't ask), not cheap, but a good knife. The G10 is thicker than I would like and the finger hole is not solid for some reason (not a big deal but you can feel the two separate pieces of G10). Don't buy one new, look on the exchange. I passed one up for $170.00 used. I was going to get another one as a back up to my current Emerson but it is just not needed, never an issue with my current one.
I also have the 5.11 version (original master), great knife, thinner than the Emerson, nice blade, solid finger hole (nice and smooth, good attention to detail), thicker, sturdier blade, it is larger but feels good in your hand. I wish this was a wave Karambit. I have been looking to buy another one so I can make the blade a wave myself. (not the zip tie but working on the blade itself)
Even though the blades are really short/small in length, every time I pull it out to cut something in public I get looks like I just ran over the neighbors puppy, even my wife says it just looks evil. I treat it as a utility blade and use them often. I carry the 5.11 more often due to it being less expensive and more comfortable to carry due to its thin profile and better feeling in my hand.
I do like the way a Karambit folder feels in the hand, the finger hole makes for a very positive and secure feel.
Good luck in your search.