I got the Ketzer Finny's in today and used them to test on a few quilt squares. The cut feels similar to the Kai. I have 8" KF and 10" Kais, and the length of the cut is close, with the KFs being smaller and easier to handle with a sharper point.
I won't know how they cut out a garment for a few days, or if they will allow for the same speed, and I'll report then.
These are similar to the 7000 series Kai I have; KF is only right handed (the Kais are lefty), but it is not a hindrance. So far, other then feeling a little lighter then the Kais, they work as good as them.