Dark arcangel question

[MoanaLisa]

I'll cast SW-D when I'm at about 70% mana on long fights. I use the other stuff on cooldown. As far as I'm concerned the only other time to really use SW-D is when target is under 25%. At that point, I've been working with a very bursty rotation that combines SW-D(x2) with Msp(x3) and MB.

But only then.

[zsun]

I usually cast SWD at around 20% mana AND when neither Shadow Fiend nor Dark Archangel is going to be available anytime soon. So far for me, casting 1 or 2 SWD under these conditions would give enough mana back to last until at least one of the spells above becomes available (usually DA will be the one that becomes available since it has a shorter CD than fiend). Any SWD casts after that would definitely be within execute range.

It also depends on what you did during the fight. For example on Magmaw, my RL simply told me to stay on the boss so I use absolutely no mana on the worms. However if I did dps the worms, I probably would have used a lot more mana and hence a few extra SWD would have been cast to sustain.

[New]

Fights where we have to use Mind Sear are killers on our mana, especially because it does too little damage for its mana cost. However, that is another topic which blizzard says they are already looking in to.