Bassbob
Emissary
In 31 years now of LE experience using all different weapons, handguns, shotguns and patrol rifles in all kinds of incidents I can honestly say I never used a pistol grip shotgun. I've fired them on the range in controlled environments and that's all I can say about them. I'm sure they have their place like any firearm does. All I can say is train with what you have and what you intend to use in their roles and let's all pray none of us on here ever, ever have to use any.... Just my two cents worth.
I trained with one for a long time and used to be pretty accurate from the hip, but it was never really a good tactical shotgun. There are situations they can be handy, but none I am ever likely to be in. Such as breeching ( which can be done pretty easily with a regular shotgun anyway) or concealing.
That pistol grip pump today.