T13 4pc bonus is fairly crappy, not worth upgrading until 410 pieces.
2 T12 391 pieces + 2 T13 397 pieces may be better than 4 397 T13 pieces?
I recall Blizz saying the legendary works well with pet users (locks obviously), if so, this should also apply to shadow priests and if THAT'S true, would T12 2pc prove even more beneficial to spriests with DTR since it reduces sfiend cooldown/increases it's damage?
I still have heroic T12 shoulders/robe/legs, just wondering if I should equip two of those instead of 2 397 T13 pieces.
I'll experiment in an LFR tonight, but would love to hear some thoughts on this.