I think the Peacekeeper is a pretty great gun. Good damage, accuracy's decent, recoil's manageable (provided you fire in bursts) and it looks cool to boot. If you ask me, the Peacekeeper is the main attraction in this map pack because, aside from Chaos Mode in MW3, no map pack in Call of Duty offered anything else other than mere maps.
Misete agemasho... Karnoffel no shinsui wo!
(Let me show you... the true essence of Karnoffel!)