If you get a chance check out the November issue of Tactical Knives. They do a great review of the SOG Throwing knives and Spirit.
Here is what he said about the Fulcrum throwing knives:
Built For Balance
The two throwers sport a unique balancing feature on the blades, giving the user the option of changing the weight distribution of the knives. Constructed of brass discs connected by a screw through the knives, these weights can be adjusted anywhere along the handle of the knife. The knobs are easily tightened by hand, and there is a large flathead screwdriver notch should the user want to tighten or loosen it more. I talked about how I like to throw bigger blades, but what happens when the small blade starts acting like its big brother?
According to the author he likes the Spirit and here is what he said
Broom of Doom
I attached the piercing weapon onto the end of a broomstick, stepped back about 20 feet and took aim at my pumpkin foe. On the second try the tip went through the pumpkin cleanly and into the wood behind it. I have other spears, but the head on the SOG Spirit is smaller, so it can be thrown farther with less effort. This size spear, more of a javelin, is rare on the market and is a welcome addition.
I suggest that if you get the chance go to the news stand and get this issue of Tactical Knives.