In my opinion, the need of a high damage OH to maximize DPS for Mutilate build is a great misconception. My argument is that, MH weapon damage will dictate the overall Mutilate damage output and the impact of OH weapon damage is fairly muted.
In the following test, Mutilate damages are compared across a list of fast daggers with speed less or equal to 1.6 as OH and Gladiators Shanker as MH. Assuming a 22% crit rate and 1400 AP.
First, without DW SpecWith DW Spec,As the 2 graphs illustrated, the difference between using a high damage OH weapon and fast but low damage OH weapon is not all that significant. In terms of percentages, the differences in Mutilate damage between using a Warp Splinters Thorn and Gladiators Shanker are 7% and 5% for 41/x/5 and 41/20/0 respectively at the assumed case, and 11% and 8% for 0 AP 0% crit respectively.
In other words, you will be doing a whopping 7% more Mutilate DPS using a Gladiators Shanker vs. Warp Splinters Thorn, ignoring weapon stats (less than 3% of overall DPS which could very well be made up by weapon stats). The primarily explanation for this is that the +101 static damage component outweights the weapon DPS component.
The impact on poison damage depends on Envenom usage in DPS cycles. Instant Poison should add the most DPS if Envenom is used as an filler finisher between SnDs . Your DPS from OH poison procs will increase by as much as 40% (1.8/1.3 - 1 ~ 40% increase). On the other hand, benefits on Deadly Poison OH will not be as obvious.
OH Enchant proc will be more frequent with a slower weapon, but the difference is fairly marginal IMO. Here is a rough translation/calculation for Mongoose (1ppm), assuming a +to hit is greater than 5%.
Definition:
H = 1 - Miss Rate = 1 - (25 - +to Hit), Hit
WS = Weapon Speed, second.
Proc per Hit = (1 proc / 60 second) * (WS / swing) * (swing / H) = WS / (60 * H)
Total number of OH hit per second
= Mutilate + normal
= (1 / 6 sec) + (1 swing / WS) * (H/ swing)
= 1/6 + H/WS
= (WS + 6H) / 6WS
Multiply the two equations:
Normalized Proc Per Second (PPS) = (WS + 6H)/360H
Using the derived normalize forumla, and given a 90% hit rate (+15% to hit), Mongoose procs every 48 seconds and 45 seconds for 1.3 speed and 1.8 speed weapons respectively. Not that big of a deal IMO, unless there are some 2.5 speed daggers out there, which shall proc every 41 seconds. :p
Conclusion:
- A high damage OH needed for Mutilate to do good damage is a myth.
- The difference in weapon damage is largely offset by the static +101 damage component of Mutilate.
- Rogues need to find the OH with the best stats, for both PvP and PvE Mutilate builds. I would suggest Blades of the Unrequited for PvP rogues (3 gem slots for +36 stamina) and Guile of Khorazzi for PvE rogues (24 agi, 50AP).
- Add some clarification at the last paragraph above conclusion.
- Added impact on Enchants and Poisons.