E2S was harder on our group, mainly because the amount of damage quietus did at the end caught us off-guard pretty badly. Our first clear was because we decided to tank LB it instead since we had no mitigation for one of them and it kept killing us. As long as you don't get the damage down, the DPS check is highly forgiving.
E3S was surprisingly easy. E2S hit harder (Quietus) and you had to dodge adds faster toward the end than E3S's mechanics.
The first phase of E4S is, by far, the hardest part.
