It’s important to note that as of patch 3.3.2, Glyph of Disease will no longer cause Pestilence to ‘roll’ the AP value present when you applied diseases. Instead, whenever you case Pestilence to refresh them, diseases will look at your current value of AP (and then use that number until you cast Pestilence again). As such, one doesn’t have to worry about lining up trinket procs at the start of the encounter. This makes GoD non-competitive for a single target, but still a must for a multiple target encounter.