This ability is specific becouse it strikes the enemy not just with your main hand but with your off hand weapon too. Again, slower weapon do more dmg but the same amount of hits becouse I am talking about an ability (not autoattacks). For that reason its better to swap your offhand weapon for some slower weapon which could be
https://www.wowhead.com/wotlk/item=5...oodvenom-blade
or another Havoc axe. After your
Killing spree ends, swap back your offhand to the faster axe. This part is questionable by many pro rogues. The dps gain is quite straight if you are talking abut the ability dmg output, however there is a cost becouse weapon swap causes reset of your autoattacks timer when you swap weapons back. Its not very clear if this cost is higher than dps gain from the ability itself. But it is clear that any possible boost of your usual
Killing spree with something like
Blade Flurry definetly worth to swap for slower offhand weapon, if you cast
Killing spree against multiple targets. The typical situation is Valkyres during the Lich King fight.
All in all it is better to swap for
the slowest possible weapon for your offhand during the
Killing spree ability.
Prepare the
Instant Poison for your weapon you will swap as your offhand if you assume the targets will die relatively fast and you are more or less sure that you will use
Killing spree against multiple targets. A good example is spikes on Marrowgar fight. But probably there is no other situation when it is good idea to do it. If you are true minmaxer, you can prepare two variants of slow weapon for your offhand. One with
Deadly Poison when you cast
Killing spree against single target and one with
Instant Poison when you cast
Killing spree against targets which are dying fast.