Back in the very early 90's while sailing way upwind at Diamond Head with Robbie my fin looked a lot like Barn's 2008 "copy".
My conclusion then was it neither added nor subtracted from performance.
I guess the next "latest" trend will be to go away from stiff materials like carbon fibre to try to match the flex of whale fins.
Dam it!! I knew the 70's windsurfer one design fin was way better than the stiffer plastic fin they've been doing now for twenty five years.