Originally Posted by
fierydemise
Sure but so does an SF ambush.
With Subterfuge you do ambush->ambush at the cost of 120 energy and you gain 2 seconds of FW uptime.
With SF you do ambush->backstab at the cost of 50 energy, in the 70 energy you saved you can do an additional 2 backstabs.
So the question is does 2 seconds of FW uptime and 2 ambushes out do 1 ambush and 3 backstabs? In MoP the answer was yes although not by a lot especially after Glyph of Vanish was fixed. If WoD where the damage breakdown has been shifted and the net damage proportion of rupture has been increased from 5% to 20% it seems plausible that it doesn't.