Both are good in their own rights. I personally prefer the looks on Fatebringer, but WoC IMO is more fun to play with because of its versatility on the second perk slots. Need to reach farther? Okay, cool. Hammer forge. Enemy charging at you constantly? Okay, cool. Speed Reload. Dealing with a sizeable crowd? Okay, cool. Explosive rounds. Notice that if running the latter with FB, it has a chance to mess up the firefly perk, so it's kind of a waste of space. Versatility and being accurate while dumping rounds into your foes makes it the better choice. Only thing that sucks about the WoC is that Void shields are almost non existent. But it's still an elemental primary regardless, and flat out better than Atheon's Epilogue since Auto Rifles sucks atm.