The Pecheneg is more akin to the way we use the Squad Automatic Weapon, meant as a lighter support weapon that nevertheless can dump a lot of firepower and is a bit longer-ranged than a 7,62x39mm AKM or 5,45mm AK74. They are real handy at night, when a long burst from a MG-caliber weapon is the universal symbol to the enemy for *throw grenades here.*
Like the RPK and RPK74, the Pecheneg does not have a quick-change barrel, limiting its sustained fire role. But that is not the role for which it is meant, and the commonality of parts and components with the PK/PKM/PKT means that the troops are already familiar with it and there is a good parts availability in the field.
In all, the PKM is around my #2 favourite tool in the toybox, depending on the exact job to be done and the condition of the individual examples available. But nothing, not the MAG/M240, not the PKM, not the MG3, NOTHING is perfect in the auto weapons biz. And some things could be better.
Loves me some Hk21 ......:o)