I'd say it's a situational piece--Enmity definitely helps, but so does VIT+2. If you're fighting a hard hitting mob, I'd say use the Honor Sword. But if you've got trouble holding hate with too many DDs in your party setup, I'd say use the Grudge Sword.
This sword is easily interchangeable with Honor Sword. Both are situational weapons. If you're in a party where the DD'ers are taking too much hate, switch over to Grudge Sword. If you're soloing or in a party where you're not having trouble holding hate, use the Honor Sword for the +2 VIT/MND and .5 increase in DPS.