Originally Posted by Aldriana

Wound poison, in the absence of poison boosting talents like Assassination has, actually does more damage per attack than Instant; it does roughly 40% as much damage per proc, but procs 2.5x more often so the damage per triggering attack is slightly higher. Under normal circumstances, this doesn't matter as you're getting a lot of bonus procs out of Deadly Poison, which helps Instant Poison a lot more than Wound (due to its higher damage per proc). But if you remove DP from the consideration - as is true for Combat/Sub thrown weapons or double direct damage potions for short fights - Wound Poison pulls ahead in raw damage output.