Someone help me out with this.
The talent pain and suffering, you'll remember, is the one that gives mind flay a 100% chance to refresh the duration of shadow word: pain on the target. So in theory, you'll only ever have to cast sw:p once per fight.
I had high hopes that this spell would make life easier for me by simplify spell rotations, particularly on long boss fights, but I'm beginning to wonder. In the dark, fur-lined recesses of my mind, I fear we have swapped the small pain of watching a dot timer with something superficially easier to use but harder to master.
My understanding is that each 'refresh' of shadow word: pain recalculates damage based on your spell power when you start channelling mind flay. What that tells me is that there's no point in micro-managing trinkets, buffs and debuffs to super-buff sw:p anymore — the significant factor now is when you cast mind flay.
If you cast sw:p before any incremental effects on your spell power (by this I primarily mean trinkets and self buffs, things you have some level of control over) it's going to tick along at it's base level quite nicely thank you very much. It might tick once or twice, say, before you get a full stack of shadow weaving. At that point, if you cast mind flay, the damage of sw:p should, if I'm right, be recalculated with the higher spell power value. Pop a trinket or two at this point, mind flay again, and sw:p's damage will be boosted again.
But ten seconds later, if any of those buffs wear off and you cast another mind flay, sw:p's spell power is going to be readjusted down, right?
If the damage is recalculated in-between mind flays, it doesn't matter when you cast sw:p so much as when you cast mind flay.
This thought makes my head hurt. Am I going to have to track mentally what buffs were active when I last cast mind flay, to avoid accidentally gimping the spell when I mind flay again? Does it mean that when we use trinkets to boost the spell's power we should avoid mind flay for as long as possible to get the maximum benefit?
Also, on a small tangent, is sw:p still our priority spell for trinkets, or does the new vampiric touch coefficient trump it?
So many thoughts, so few brain cells...