On Abyssal Commander Sivara its almost around a 7% difference in dps in favor of Havoc over Unholy.
Radiance of Azshara is around a 7% difference in favor of Havoc over Unholy.
Blackwater Behemoth is around 11% difference in favor of Havoc over Unholy.
Each fight Havoc is ahead of Unholy. Orgozoa is the closest but still in favor of Havoc but only 100 dps between the top performers. These are just based on the top performers. I could average the top 10 on each fight together and then see the dps difference but im being lazy.