For me, and this is also the only GOOD primary I have since I only started playing a little over a month ago, its Nirwen's Mercy with the perks from the IB vendor. Max stability with super fast reloads after headshot kills(witch is super easy due to the awesome stability) and that the radar stays active is killer in PVP. The only thing I can complain about is the relative slow rate of fire compaired to its closest rivals, Grasp of Malok and NTTE. I also like Red Death, but I only have the Y1 version of that one atm, but its not as quick and accurate as the mercy.