Soul Mastery or Dark Mastery?

[biostem]

I'm mainly interested in darkest night, so soul mastery seems like the better choice, since you can get it sooner, but dark mastery has a faster-animating hold and a PBAoE damage attack.  From my experience, other than for a bit of flavor or as expendable cannon fodder, the PPP pets are kind of useless.  What are your thoughts?  Thanks for reading!

[FupDup]

Another consideration is that Dark's variant of Darkest Night has slightly stronger values. 

 

IMO I would base the decision on if you need/want the extra PBAOE attack. Go Dark for AOE, go Soul to save slots. 

[Uun]

I went Dark on my Elec/Bio. Engulfing Darkness is quite good. Smite is fast animating and has a 12s recharge, allowing it to be a functional attack (Midnight Grasp has a 34s recharge).