[1.2.381] The Wind

Are you saying the can fj more often and thus travel faster at 100/100 than 140/123 or that they travel a further distance per fj at 100/100 than 140/123?

You travel faster at 100/100 than 140/123, which means you land sooner and thus can attack sooner/Flash Jump again after a Flash Jump. Night Lords probably find it more advantageous to have the Jump, but I never found it terribly useful on a Shadower, and it's only useful on a Dual Blade because they need it to use Flying Assaulter.