Pros:
Lots of Pokemon with the ability Sniper gets Lazer Focus
Z-Lazer Focus Raises attack to Choice Band Level
Cons:
Kingdra, the best user of sniper is better running Z-Focus Energy since it gives him 100% Accuracy on Draco Meteor and Hydro Pump
Beedrill loses Sniper Upon Mega Evolution
Most Pokemon who gets Laser Focus is better running other moves
if Marshadow uses Z-Laser Focus, it loses Marshadium-Z, Focus Sash or Life Orb (all really important items)
Dont use Laser Focus