HI Mitch !
maybe if you are going to cut off the fins and NOT put in plugs or boxes [??!!] , you could shorten the sideys 1/2" as plugging would have done , and have a larger [than , say , 'GS' sized] back fin , if it is a 'THRUSTER 'feeling you are after ?
" How about you (sorry to hijack this thread!)? How do you find the Walden?"
as I posted on the 'chip's pic[k]s ' thread , 'I am still LOVING this setup !!' the most of all I have tried .
So far , what I have been feeling with this setup , versus 'traditional' fins , is the ability to turn a bit more 'top to bottom' ... and hold . Where previously , with four smaller 'traditional' fins , with the board's thickness , and width , and flatness , and wide , thick , flattish tail ....[combine this with only 63kgs rider weight ] ... there was some slip and skip during turns [and I'm not really a big fan of that !]
cheers !
ben