I have looked at this skill a few times. I never choose it as:

1. It takes 4 seconds to arm, if you can predict a mobs movement 4 seconds ahead, then you don't need this
2. It does 11 Damage, plus 24 for Daedra or Undead, so what, 35 points max? Unless this is DoT and the tool tip is unclear, but even 6 seconds of 35 damage per is weak. Unless it starts to really scale as it levels.
3. There are much better ways to snare/stun an enemy with attacks that actually do damage.
4. The Mob will aggro on you as soon as you cast it (I am guessing, as they aggro on everything else cast towards them). If this is the case, you lose the sneak critical initial attack, which usually stuns, like from a bow attack or others.

I feel the same way about Daedric Rune too.

thx about to take that one