Dark Mastery vs Soul Mastery?

[BazookaTwo]

I'm considering either one for my Beam/Psi Armor sentinel. Both have a melee attack, a hold, and a version of Darkest night. Which is typically better?

 

I know Soul Mastery has a cooler looking hold. 

[FupDup]

These are the two main differences:

1. Dark's melee attack has lower DPA and 1 less proc option, but it does have a faster recharge so it can be spammed more as a filler attack. Beam is a somewhat busy set so I think the slower and heavier hitting Midnight Grasp makes more sense here. Handy chart:

 

2. Dark has a PBAOE option in the form of Engulfing Darkness, but Soul has no such option. 

 

So if you just want the ST melee I'd go Soul, but if you want a PBAOE bonus attack I'd go Dark.