Our group didnt notice any enmity issues, enmity is same as before but ppl have easier acces to higher ilvl and since tank enmity scales slower than dps enmity due to using vit accessory it can cause some problems for lower ilvl tanks. You can always use some dps accesory anyway cuz you dont realy need 10k hp except for i think coil9(we are at t8 still). Our tanks usualy stop going for vit at 7,2/9k hp and use dps accessory.

But what we encoutered is some weird mob behavior since 2.3 or one of the hotfixes after it in T6 and T7.

What is happening in T6 is that when slugs spawn and our offtank uses cyclone to get aggro, they go for main tank(0 enmity since hes not attacking them) and once they reach him do nothing and then go back to offtank that have fullaggro whole time. Similar thing happen in T7 with adds that on spawn they go for random party member, usualy our bard or smn(again they dont even started to attack those ads = 0 enmity) do nothing to them and then go back to offtank. Its not like before patch when you didnt react fast enough before the mob "activation" and they gone usualy for healer, hit him with skill and go back to offtank. This is not the case, our tanks have 100% aggro on them.