Sparrow was recently unlocked on an event and since then it has been my operator skill on all my loadouts.
Aside from unlimited ammo, long range shots, there are several other perks it gives you.
1) Kill Group Of Enemies
With sparrow you can kill multiple enemies with a single bow. This can be specially useful in Domination and Hardpoint matches, as in these matches enemies need to guard certain point and are usually near each other.
2) Destroy Scorestreaks
UAV, sentry guns, heli, vtol — you can destroy every scorestreak using sparrow,
3) Destroy Vehicles
Enemy hiding behind a vehicle? Change to sparrow and destroy the vehicle, easy kill!
So are you going to change your operator skill to sparrow?