Some people say there is a larger nic release due to surface area, or something along those lines.... But yeah I have no idea why fine cut is preferred . The flavor, IMO, is comparable to lc. The few times I've purchaced fc I've been unsuccessful, and pretty much wasted a quarter of the can between spillage and mudslides, to borrow a snus term.
And snuff, forget it. tried a pinch out of a co workers can, and that was all I needed to realize I wasn't cut out for it. Copenhagen snuff,to me,was like trying to lower lip an unbaked prilla... in other words, god damn impossible for me to control.
So to answer, I don't know any advantage of fc.
Long cut for me when dipping.