I remember reading somewhere that the most appropriate time to use your Gargoyle is after Mirror of Truth procs, or if you do not have it, Unholy Strength. I have also read that using it during Heroism/Bloodlust will maximize its dps. When do you use your gargoyle? In an environment where there is no Shaman, I tend to use mine when my Mirror of Truth procs (or if I'm lucky Mirror of Truth and Unholy Strength), otherwise I use it during Heroism. I have yet to actually test when the best time to use it really is, but any input from other players should help with that.