Isn't it true that the best performing fin wouldn't have any rake to it? Is the only reason for the rake so that if you hit someone or some kelp it will ride right over it? I don't know I heard that somewhere and thought I'd run it buy you guys.
If you need more surface area but don't want height rake can be the answer.
Because surf conditions and board configurations vary so greatly there is no simple answer to you question.
Vertical fins do not offer the drive that raked fins do.
There is a hell of a lot more to the over all picture of fin configuration though. Foil and flexibily as well as template outline are a big part of it. Different fins do different things to performance. Everbody wants something different and every change in shape is a compromise.
rich or any other fin man,
what is the main difference between your old classic skegs and your modern 9" fins? anything better about the skeg? i have never had the opportunity to ride one of the old boards.