This is a topic that I find quite interesting, and I appreciate the fact that Floyd brought it up. No question in my mind that fins will affect the performance attributes of any board out there, yet I think that the basic premise of most magazine board tests is to test with the stock fin(s). There's clear merit to this, if only because it represents the complete retail package concept offered by the brand. Nevertheless, one wonders how much direct input that the board designer/shaper has in determining the design and quality of the stock fin(s) that's ultimately matched with the board.
In contrast to conducting board testing with the stock fin, it would be very informative and undoubtedly more revealing to conduct a test using a single "aftermarket" benchmark fin that's recognized as one of the best in the industry. I think that would lead to a more unbiased outcome that would say more about the character and the particular attributes of a board's design and performance. Although it wouldn't remove the subjectivity that's always inherent in board testing, it would improve the credibility of the test model.