Let me state that, I've tried a few fluorocarbon lines. P-Line Fluorocarbon, P-Line Halo, Seaguar Invixz, Steez FC, and limited use of Berkley Vanish.
Hands down, FC Sniper is the softest FC to date. Very supple, smooth casting. Knot are very good. Line diameter is small for # test. There are a couple of cons though. 1, it has a little bit more stretch, than i anticipated. And 2, costs and availability.
Cost wise, it's basicly twice the price, per yard.