PK's get all the advantages.
PROS:
They decide where the fight takes place.
They decide whether to initiate the fight.
They have the element of surprise (priceless)
They can use blue as a subterfuge.
If killed first they can return to the fight quickly (see first point)
If they get the kill they can escape with loot quickly or decide to leave loot altogether without loss.
Besides name/Guild there is no way to identify or tag a serial killer.
CONS:
Parcel runs to maintain blue/standing.
PROS:
They decide where the fight takes place.
They decide whether to initiate the fight.
They have the element of surprise (priceless)
They can use blue as a subterfuge.
If killed first they can return to the fight quickly (see first point)
If they get the kill they can escape with loot quickly or decide to leave loot altogether without loss.
Besides name/Guild there is no way to identify or tag a serial killer.
CONS:
Parcel runs to maintain blue/standing.