I recently became a fan of this gun myself. I used it to complete my Impact challenges. My favorite setup for this gun was:

Blind Eye Pro, Assassin Pro, Steady Aim Pro. Impact as a proficiency, Silencer as an attachment.

I run the specialist package with SoH, Quickdraw, Marksman. My secondary weapon is the SMAW.

With this class I would use the SMAW to take down any UAV or Counter UAV and I would use the M60 to take out any choppers or advance UAV. Id use a combination of both for AC130 or Reapers. This gun also destroys assault drones, recon drones, sentry guns and any other enemy equipment. Even with a silencer on this gun is still loud so even though you dont appear as a red dot on radar people around you will still hear you. I used Steady Aim as my third tier perk because I found that this gun was devistating while hip firing at close range.

Grip or Kick make this weapon easier to manage at longer distances but controlled bursting works fine. I set my specialist perks up in that order because I feel the 9 second reload is a suicide mission on its own so the faster I can unlock SoH the better. This gun also has one of the slowest ADS times so adding Quickdraw as a 4 kill reward is my best option. Marksman is a given but i find that extremely long range encounters with this gun are usually bested by most ARs despite the fact that this gun does higher damage. The high damage doesnt make up for the supreme accuracy and firepower of most ARs.

Im a run n gunner and I found my setup to work very well for me. I also like this gun with Attachments, Grip+Rapid Fire.