There is nothing difficult about this raid, other than blizzards dumbass people making it hard. With people dying from falling damage on Jailer, Anduin doing 20k damage to people every 1.5 seconds ( this isn't even his dot damage ) or random thing like 1 dark circle being hit by 2 yellow circles bug leaving the last person alive with no one to go to, or my favorite, or my favorite, give certain covenants giant BLUE CYAN colored AOEs on the ground, then make the same spell from bosses.. SMALL CYAN COLORED AOE CIRCLES, esp. during the zombie phase. Well done blizzard. Have small circles that someone hit you even if you are out of them or can't see them because theres like 20 zombies on the ground. I could go on and on about how this is the worst raid ever create in the history of any MMO i've played. Not to mention the vastly different Tier sets and how some are obviously superior than other classes.
Lets see what more useful.. a Infernal that drops every 5 Chaos Bolts or 3 rain of fires, or some crappy Fury of Elune every eclipse. I mean blizzard couldnt think and say... Hmm maybe a instant cast full moon that always crits would have been a better choice for the tier set bonus.
No amount of nerfing will matter, when the fault lies with blizzard, and blizzard alone.