Why is this fin sooo favorite in real-world conditions is quite hard for finproducers. Since the tectonics doesn't have a lot of lift, or very less drag. This fin has almost no grip, and you can actually see the boards angle of attack with the water is bigger than most other fins.

To be honest with you, I also own a tectonics falcon f1 25cm. The rest of my tectonics collection is sold, since all my personal records are sailed with Select fins. But, I still like the tectonics falcon f1, because this fin is pushing the sailor in the right direction.

This fin is a good example of "slippery" fin, slippery is a good habbit for "average" surfers like me & you. Why would a slippery fin be faster in some cases, I am thinking of 2 reasons. (1) You automatically take a longer fin 2-3cm longer (better in big chop) without overpowering, (2) and your subconscious go in the right mode (the "I don't want a spinout"- mode  instead of the "power"- mode). Conclusion: for extreme choppy waters a slippery fin could be the answer.

However a lot of other sailbrands have a similar design (copy?), have test them all, but here is the list, maybe you guys know more.

Select Devil   (better in extreme chop/ deepdown wind, less topspeed)

Choco Mach F1

Deboichet SL5 ? (SL6 or SL7 ???)

Vector EX