Generally, 1/3 GCDs will be a SS (MP regen) or a SE (10 BB). Using Bloodspiller reduces this. Also, so many people saying "TBN is amazing!". Well, yes and no. I know none of the current dungeon bosses hit me hard enough to ever proc it and again, due to the nature of Bloodspiller being on the GCD the offensive benefit it gives is limited. Looking like the early math is pointing to TBN being a DPS loss when not in Grit at the very least.

It seems that "stance dancing" is more encouraged than ever now as well because BW+Delirium is just so much better than BP+Delirium. I know I always drop grit for it if Delirium is available.