The healing requirement is a step up from last tier but not by much. It's nice that e11s already has some mechanics that hit harder or have more frequent damage like Cycles or Burnished + Light Elemental Break right after but one hardcast for each Burnished and rest with oGCDs/ lilies ended up being enough, so there's definitely room for a lot more. Nonetheless, I like Cycles best so far because they have a nice mix of constant, raidwide and single-target damage with enough time between hits to not make it into a mindless GCD heal spam fest but keep you constantly engaged.
And I agree that e12s seems to be a mitigation check mostly, at least from the part I've seen of this fight. Once we shifted around our mitigation, knockback with icicles right after stopped being a problem.

The focus seems to be mitigation checks and one-shots rather than more frequent or even constant damage that shifts the responsibility for surviving to healers rather than tanks/ dps. Right now you're just dead if people forget their mitigation, nothing a healer can prevent. They increased the damage, which is good, but it still feels lacking with the focus on one-shots.
I'd prefer an encounter design where mechanics don't hit as hard, your heals don't heal as much and damage is more frequent instead of extremely high but rare damage spikes that need to be mitigated to death and are healed with an oGCD or two.