1.7.x Gesture of Pain & Psiblades interaction?

[ReploidArmada]

I've heard it said a number of times in the past that Psiblades and Gesture of Pain don't interact very well, but that you still want both of them as Doomed. The logic behind taking both makes sense to me, but I'd like to know for sure: What does sustaining both Gesture of Pain and Psiblades do for you? Does the active stat boost from sustaining Psiblades matter for the Gesture attacks, or is it just the passive weapon damage and physpower that matters?