Flourocarbon is junk on your baitcast... I dont think it was made for anything but leader material for those fly guys...why the strength would vary from a whole spool on your baitcaster to just a leader I am not sure...I work at GI Joes, and have used the berkley vanish 10# on my baitcaster and busted off 5 steelhead...we have had 2 spools returned to us already as defective...is it the brand or just flourocarbon in general? dont know.... hope this helped you...