Fake Shot before Invisible a viable build?

Although they both have the same speed, same mob number, and invisible shot does 50% more damage per enemy, fake shot has some distinct advantages.

-It can shoot close range
-stuns mobs
-uses NO BULLETS

With a cleric to heal you, this make almost any infighter or other melee class training spot useable for a gunslinger.

Do you think it's worth maxing before invisible shot?