Weird ass fin: gimmic or functional?

http://www.turbotunnel.com/

 

Has anyone tried one of these and can comment?

 

Cheers,

 

J

Horrible fin from my experience. 

Been around for decades. Total gimmick. I know a few folks who got them early on. Reviews were “thumbs down” across the board.

The comment usually goes like this “They do marginally improve noseriding, but it is not worth what you give up in speed and manuevarbility. They arn’t worth it.”

Bogus

doc…