What is the Advantage of a pistol grip shotgun?

A pistol grip shotgun ( they made a .410 Handy Gun with a ball sight ) is useful with small shot or if you are using slugs. Careful, the length of the gun must still be legal. Often dramatized in movies ( MAD MAX, sawed-off 12 ga. with a pistol grip is one of many ) they show the shooter using one hand stuck straight out......No way !!, The blowback will break your wrist or literally fly out of your hand.