not sure i just recently started using them more frequently, in year one the vanguard offered a bounty all the time for getting two kills at once with a fusion rifle but you never see that anymore. they need a buff in a bad way which is sad considering they are the closest thing we have to ray guns and we are supposed to be futuristic space warriors. i currently run susanoo on warlock, phanta rei on titan, and long far gone on hunter and of those three i would say long far gone is my favorite, if vendor sold one that offered a stability perk i would run it on all three characters.