Spirit Void vs Essence Sap

I'm at a point in my tree where I can take either Spirit Void or Essence Sap for the same cost of nodes, without impact.

So, which is better? Below are the differences (there's other bits but they're the same on both):

Essence Sap:

0.6% of Attack Damage leeched as mana
+2 mana gained for each enemy hit by your attacks

Spirit Void:

0.8% of Attack Damage leeched as mana

Now that my damage is pretty high (level ~65ish at time of writing) is Spirit Void > Essence Sap?

Or will I miss the "instant" mana gained from the +2 per enemy hit?

I run two auras so have a very small active mana pool.

Thanks!

A

What a lot of people do is they just take the first mana leech node in the Spirit Void / Vitality Void cluster and then also take the life and mana leech hybrid node in the middle. This gives you .8% mana leech which is enough for most builds and .4% life leech as an added bonus.