Even the Boomers seem to think it svcks; even with their Explosives skill at 92 and their Melee weapons skill at 17, their AI seems to determine that their melee weapons have a higher DPS than their grenade launchers, and equip their melee weapons instead.
According to DPS calculations in the GECK, full clip + reload time for the rifle is 41 damage. For the rifle? 53. For a tier 75 gun, it really is lackluster if it just has 12 DPS advantage over its tier 25 predecessor, for a price tag of 3900 caps higher and 6 PWUs heavier.
EDIT: Well it seems that the Boomer issue may have been caused by my forgetting to deactivate a failed attempt to make a 40mm buckshot alt ammo. But still... the DPS rate isn't really that good for a Tier 75 weapon regardless.