Nah not OP. Without the Turbocharger, they are only good if you choose to fight it in a full on "ads-and-spray" duel.
Since you can hear the wind-up, its so easy to outplay it. Just be smart and fight behind covers etc etc.
With the Turbocharger, they are viable, even good but not OP. Considering that the turbocharger is a golden tier item, it SHOULD make them good, but so is a R301 or R99 with purple mag and barrel.
Also, both the Devotion and Havoc loses ground compared to many other weapons on the mid range. I would take a R301 before a Havoc with TC any day of the week on that awkward range where a 1x-2x sight is a little bit to weak but 3x+ is too much etc.
