I picked up my iS76 monday. It does come with a (red) Drake Slalom Pro 32cm fin. The iS86's are supplied with a 34cm fin. As there is only .6cm difference in OFO tail width, I guess the fin range is going to be similar (only 2cm difference in max size fins)!! As the iS76 is initially intended for "high wind slalom" I think that the supplied 32cm fin is intended more for slalom & not for speedstrip. I bought mine for moderate wind GPS-SS flat water speed (less than ideal speed board days). This will accompany my S100 (light wind GPS speed's). But I think your correct in saying that a much smaller fin is needed for the speed strip. The iS76 looks very different C/W the iS50, definetly looks more slalom orientated (doest'nt look much smaller than an iS87, just a bit thin & lighter). But normally, what works in slalom also works on the speedstrip, so hopefully it should be good for 40k plus.