I am the RL of a guild about to start pulling heroic spine, and I have told all our dps (retri paladin, arcane mage, subtlety rogue, SV hunter and SP) to get the VP trinkets for this particular fight. I have played all those classes myself besides SP, so I kinda know the extreme impact these trinkets bring to them, but our SP told me that he isn't sure about the trinket as opposed to heroic Necromantic Focus. He claims he'll probably do more damage on the tendons thanks to the mastery.
I told him every single guide on the internet suggests those trinkets, but he wants to know exactly why. I couldn't provide a valid argument besides "it's a 2290 bonus to your best stat", because I know fuck all about Shadow Priests.
So, if you guys could shed some light into the situation, I'd appreciate it very much.