Shootist16 is too modest. He has written a great review on the KFF which I have taken the liberty to post below:
I carry a bead blasted black micarta scale KFF daily. I don't carry it with the clip because I prefer the deep concealment of my Inside the Pocket Knife Holster. Without the clip the handle feels great in my hand, not too thick or thin. I'm sure the Ti version feels great too. I hope to hold one at the Timonium (MD) Knife Show in Dec. I also am looking forward to meeting Pat Crawford (Thanks for the tip Damon).
The micarta on my KFF has a bead blasted finish which the earlier KFFs didn't have. It really makes the knife slip resistant and is a big help during openings. The micarta is very scratch resistant. My KFF also has the newer conical shaped thumb stud which I prefer to the earlier cylindrical version.
I also have a KFF with a blunt, unsharpened training blade. Doing impact training with the trainer really points out the excellence of the handle. Never do I have to adjust my grip even after multiple hard thrusts because the knife is totally locked in the hand.
When you refer to the fencer's grip I assume that is the same as the saber grip. I agree that the knife feels wonderful in that grip. However after communicating with Bob Kasper, he told me that the saber grip is only intended for snap cuts and that the natural grip should be used otherwise. This is because the natural grip is more secure. There aren't too many folders that offer a secure natural grip hold, but the KFF is exceptional in this area.
As stated by others, the blade design is marvelous. Very sharp and the wide profile makes for large wound channels. On my new KFF, I had Pat leave an extra 1/2" of unground edge at the pivot end. Being a liner lock, the knife should be checked periodically for proper locking. After several months of hard heavy bag use, which is nowhere near common usage, my KFF trainer started to disengage during some thrusts. I sent it back to Pat and he fixed it. With the extra unground edge, should the blade close accidently, the unsharpened edge will contact the finger. A quick flick of the wrist will lock the blade back in position. The deep finger groove ensures that the index finger will be properly placed for this safety feature to work. Pat graciously added this mod without any extra charge.
I asked Pat Crawford about a Rolling Lock version of the KFF. He was going to build it, but then Bob Kasper told him that he did not like the placement of the slide bar. He was concerned that the thumb could accidently unlock the knife. Pat may come up with a design that Bob likes in the future, but for now the RL KFF is not available.
The Carnivore looks like an excellent design also. I prefer the pinky hook on the KFF handle for the added grip security it adds during withdrawals.
So in short, a great knife, my all-time favorite folder.