Energy Weapons ammunition has a built-in DT penalty (Max Charge ammo kicks some serious butt), so these weapons are potentially more powerful than ordinary shotguns. Metal Blaster is basically a unique laser shotgun, the Protectrons Gaze does the same thing in less powerful laser pistol form.
If your character has a high critical chance, any shotgun(like) weapon that fires multiple rounds at once is very powerful when used outside of VATS combat mode - Basically every beam or pellet in a blast has a separate chance to cause a separate critical hit, and a whole bunch of critical hits at once can translate to a whole lot of damage.
