Is Walden still honestly using O'Fishl fin boxes (with the sily Z-Clips) in a 2+1 board? Thats strange...there have been advances since 1997!
yes, single fins are "retro", but this day in age they serve no purpose in the water, unless gliding along a very small, slow reef break in socal, or under an old, long log.
Not to bring up the thurster issue that has been tossed around for years, but other than a thurster, even on a fish, I onlg dig the quad setups.
You can play around with a thurster setup and get all kinds of cool performances. Larger middle fin, even on my 5'10 is fun. You can put little tiny ones all around and do tails slides all summer.
If you are learning, you want a thurster setup. seriously. You can play around with "retro" ideas once you can actually surf.