Reefman - hard to believe you're having problems with knots so I thought I mention two recent experiences with nanofil. There are very few knots I can't tie so I was a bit baffled as well. Experience 1 - I came across an angler with a spanking new outfit on the beach recently which included nanofil. I watched him tie a few of the tried and tested knots and the nanofil parted at various places. On one of the knots that I used it parted consistently at the knot. Now without a setup to test the breaking strain at which the nanofil parted it was difficult to determine whether the nanofil parted at/beyond it's stated breaking strain in which case you cannot fault the nanofil. From what I experienced I was not impressed with nanofil.
Experience 2 - I related experience 1 to a friend with a similar outfit a few weeks ago and he allowed me to test the nanofil as much as I needed to. I did the same as previously and pulled the knots until it just about cut into my arms and nothing gave way!
Was experience 1 a bad batch of nanofil? You be the judge... I don't know and will need a bit more testing before switching from the tried and tested jigman.