It's rather obvious the PBP definately has the upper hand in close combat, I always get full on raped by it in bases. It's not a gun of skill, and rather just a statement saying "I got mummy's credit card, jelly bro?".
I think nerfing its firing rate would make it more balanced which requires more thought and skill and not just a weapon of sheer dominance.
Thing is, there needs to be more disadvantages to wielding a shotgun in tight spaces over wielding some semi-auto whatever... It could be lowered player speed for example.