Gave up on F1, found titanium the best, black by far the worst !
I have several spools of black, from 15lb upwards, and had a nightmare with them. The black nicked at the slightest touch of rock, spun up, horrible memory.
Always properly de-spooled. Don't trust it, and don't know what to do with them?
Switched to Daiwa Tourney, and Sensor no problems so far. Also rate maxima in the smaller sizes.
The old Ultima tapered leaders were the Dogs Danglies tho. I bought a load when they went out of production, so haven't tried the new ones. The Daiwa ones are like tow rope when compared !
Mel....