I guess with multi-fin boards the type of fin selection is critical, but for mr average like me that uses single fin board I am wondering if I should stick to the traditional swept back design fins or should i invest more money and get a maui ultra fin x-wave design which is also now used by jp 2011 boards...

The steeper the fin, the more it gathers seaweed and hampers performance.
Have a couple of different sizes so if you start tailwalking go down a size.
If you're having trouble getting upwind go up a size.

That's about as far as it goes for me, "mr average can't loop even though he had plenty of chances today"

Leave the obsessing over fins to the slalom guys. That's where it makes a difference imo...

get a 21cm freestyle wave fin. will work alright in a freestyle board. should be able to find a cheap one like that aswell.

yeah i was using a 99 freestyle with a 22 freewave fin.
21 or 23 cm will make it nice and loose on the wave. Any bigger will make the FS board feel rubbish in the waves.

for freestyle i'd be using a 16-18cm fin. 4.2-5.8sqm. so cut ur stock one down.

the freestyle fin wont be awesome in the waves but will work. look for more swept back fins with a bit of flex.

Bring back the footbal fin I say[}:)]