Utter rubbish. I use fluorocarbon for all of my fishing. I have landed barbel to 14lbs using it and carp to mid twentys. I have hooked river carp in a fast flowing river that were in excess of 40lb's (i had them right upto the bank) and the knot strength was never the thing that failed me, it has always been the line snapping that has caused me problems never the knot slipping. You obviously are not used to tying Knots in fluorocarbon. Don't just take what everyone says as the gospel truth use it a little bit more and you will soon learn that fluorocarbon has a high knot strength.
