I was trying to see what the max possible DPS for a sub-finisher build was and I noticed that Coup de Grace and Aggression appear to be exactly the same, and acting oddly. The first two ranks of each give me the same DPS boost (using hemo as my CP generator), while the third gives me a reduced number.
My base build was
Talent Calculator - World of Warcraft
With this, 0/2 = 2/0 = 1/1 (m/n being points in Coup/points in Aggression). And, the DPS gained per point of each talent is the same going from 0->1 as it is going from 1->2. However, going from 2->3 yields a lower DPS gain. As such, 1/3=3/1<2/2.
I used the current BiS sub gear for this model, except using the Blade of the Unmaker instead of the set one due to the reforging bug.