I wouldn't drop 4pc until you are at least getting 2pc 13, there's already loaddddddds of haste gear this tier so it will skyrocket regardless of one piece of offset
Absolutely....not. 70% of the time the 4pc does around 8% of my healing. the other 30%? 11%+ i'm gonna be really sad when i lose it, nothing better than it proccing when drinking a PoC /win
I wouldnt drop 4piece t12 for 2piece of t13 as holy as well.
The buff u get activates with the start of Divine Hymn so ur have 15 sec left on the buff, after divine hymn u might not need to fully heal everyone so u might not cast ur bigger AoE healing spells on some of the fights. As holy i would stick to the 4set bonus for a lot longer, till i get 4set t13 as 10man healer some fights u do use the full duration of the buff tho. Zon'Ozz on a bad combo
But to awnser ur question, either get a different piece to keep ur 4set and equip the robe (3 red gems <3) or loot it hold on to it till u have 4set t13.