You seem to forget that bosses in ICC will be attacking faster than normal bosses, I'd assume this to have a 100% uptime on bosses, as the effect doesn't just last 10 seconds, it's like Solace of The Defeated, the timer restarts each time a stack is applied.
meaning, after you've got 10 stacks, you're getting a constant 270 stam and 2128 armor.
I have a feeling this will be one of the BiS, along with Corroded Skeleton Key, which is a base 228 stamina.

