Well, I got the 2-piece bonus on this set today, and…
I’m a little underwhelmed.
Assassination version:
“When your bleeds deal damage, they have a chance to grant you Vile Tincture for 8 seconds, increasing your poison damage by 1.0% per stack (up to 10 stacks).”
In my current talent loadout, the bleeds I have are Garrote, Rupture, and a bonus bleed from Mutilate. For kicks, I respeced a bit to pick up Crimson Tempest.
Even with those bleeds (two combo generators, two finishers), against a training dummy, so absolutely ideal circumstances, no mechanics to dodge, no time off of target, the chance of applying Vile Tincture is apparently low enough that sometimes the buff would drop off before hitting max stacks, or wouldn’t refresh in time when at max stacks.
And given that the 4-piece bonus relies on having 5+ stacks, this isn’t looking like a great set of set bonuses.