Jim Six,
I carry a KFF and I think it's a great knife.
The feel in the hand is wonderful. The deep finger groove ensures that my hand will never slip up the blade. That's very important to me because about 12 years ago I cut a finger tendon on a custom Balisong knife which didn't have a very substantial guard.
One problem I have with clip carry of the KFF is that the flat topped opening stud often hung up on my pant pocket edge. In another post which you know about, I now carry the KFF in an In the pocket knife holster so that it doesn't hang up on the pocket edge.
The blade is very sharp and extremely aggressive. However, I have come to question the sturdiness of the linerlock. You can read my post under the Tactical Talk section to learn about it.
I also have a mini-Kasper in ladder pattern damascus. It's a nice size to use around the office. Although it's a bit small to use for defence IMO.
Let me know what your experiences are.
Axel