During leveling, at least (as far as I’ve made it so far) - The resource leech is too overtuned.
It’s very easy to get killed in our new portals getting double teamed by Resource Leech elites and having no way to get away.
Perhaps taking down to 10% or something similar, instead of a full resource burn would be manageable… but we still have to be able to act.
Agreed. Add to that the possible bug where even non-elite/champion mobs in a fissure level seem to drain ressources (not always, but I’ve encountered this more than once at least: all champions/elites were dead and fighting the remaining normal mobs, I still got drained constantly), and it’s just debilitating.
Watch your health, Nephalem! New powers originating from the Burning Hells have been bestowed upon all enemies inside the Visions, making them more lethal than before. These Affixes are only available in Visions of Enmity.
From the patch notes, all enemies would mean its intended. Assuming the notes are well/ clearly written. Not supporting the design though. Do life & cooldown behave as per notes?
You could be right… thanks for the reminder.
Still feels terrible, being resource drained in general and even worse, from normal mobs. Would like to see a nerf to that affix or level design.
Well… nobody liked it in D4 so they decided “hey ! lets put it in D3 as well. Lets make both games equally hated”. You know… logic 
Resource Leech is straight up awful. The second it was removed from D4 the team should’ve realized it needs to be axed here, too.
Do not let this go live, kthx