I've had terrible experiences with lighter pound tests Nanofil, which I've reported here in the past. I tried the 2# test and the 4# test. Using a fluorocarbon leader connecting both with the Alberto knot. Can't tell you how many fish and jigs I've lost with the line breaking just above the joint knot! Regardless of how lightly I set the hook - and sometimes just reeling and not setting - the line would part very easily. I even tried direct ties without a leader. Same results.
Prior to experimenting with these two pound tests of Nano, I had been a long time user of Fireline. I've gone back to it now, in the 2# test (Crystal verstion) with a 4' fluorocarbon leader and have had no breakage at all - with the exception of bite-off from pike or pickeral. Even hang-ups are broken off at the jig knot, not the leader joint.
Fireline crystal casts beautifully as well. I now have it on 4 of my crappie rigs (two 9', one 7' and one 6'6"); three of these have the 2# test and one with 4# test (for heavier jig heads). No problems.....no worries. I would never go back to Nanofil. I still have it spooled on two of my bass fishing rigs (I was sold on all the false hype at the time), but have not had any breakage problems with the heavier rated Nano - 10# & 12# tests.
Take it for what it's worth (just my opinion) and do your own testing. However, don't be surprised if experience similar results.
"A voyage in search of knowledge need never abandon the spirit of adventure."