What subclass do you prefer on your Lock? Patience and Time can get you out of hairy situations and has an ammo perk. Can't beat that with recent sniper mag nerfs. The invis is nice as well considering Warlocks otherwise need a Hunter smoke capsule to utilize invis. You have to ADS to keep the invis up, though. Arc is a very common shield type, and the gun itself hits hard enough. It isn't a high impact sniper, but it definitely isn't a low impact either. Sleeper is okay for bosses but I wouldn't main that as my heavy. I rarely even use mine honestly. I prefer my Raze Lighter, and that doesn't hit as hard as Sleeper. Just personal I guess hah.