I bought a F1 and immediately returned it because it was uncomfortable to hold in a hammer and saber grip.
I then bought the 200 Puukko. In my opinion, the Puukko is much more comfortable to hold in a hammer or saber grip. However, the flared handle end on the F1 allows for a good 2 finger chopping grip that you don’t get on the Puukko.
I also prefer the leather sheath for the Puukko to the plastic sheath of the Fallkniven. Less rattle and no need to deal with the annoying strap.
The thickness of the blades are substantially different. I never used the F1, but it seemed to be better suited to splitting wood, light chopping, and striking ferry rods. The thinner blade of the Puukko seems better suited to slicing, cutting, and stabbing.