The stat roll, firefly is way more useful in PVE and there I the same amount of bullets in the mag and Fatebringer has more impact also when HoW comes they will have equal power. The crota puke on word blocks most view on the gun while Fatebringer has a smooth and small body where you can easily see. The only reason I find the word of crota useful is in void burn areas. In conclusion, REKT.