You're right, TBN actually is much better this time around compared to what it was in sb. Different game changer. I keep looking at it as what it was before they updated it and made it better.
When it comes to trash specifically, I'm going to disagree on this one. (which is what this thread is about)
Problem I'm seeing with Blackest Knight compared to Camouflage now that I'm leveling up dark knight is that once that shield breaks, you have no defenses. Not only that but it only lasts for 7 seconds (and usually breaks before that) meaning you have to burn off another cooldown once the shield breaks. Camouflage on the other hand isn't the best mitigator, but does last for 20 seconds and provides a defensive ability that entire time.
So on large pulls, I've always felt like gun breaker has a better suite of cool downs than dark knight. That's not to say that blackest knight is bad... just I feel like camouflage is better on large pulls.
Ran as SCH, went back to Holminster Switch, my memory confirmed that prior to first boss should be a 2-3 if wall to wall. The 3 packs will be quite stressing. However Holm S is better for me compared to the likes to Doma Castle.
As per other ShB lvling dungeons, Dohn Mheg is where Recitation makes things easier and hard part after 2nd boss; Malikah Well have only an issue where they want to kill 2 revive golems in a go or DPS one pack before they revive; Mt Gulg also mega packs after second boss, that is only the time I am forced to use Dissipation.... sometimes. Qitana Ravel I have no good memory of it due to I only done it once for MSQ and never able to queued up in DF.
In any case, 5.1 will give tanks another okay-ish mitigation in the form of Reprisal changes, that ability is now Rampart v0.5. (10% dmg reduction to all surrounding enemies.... for 10s?) 30% mitigation skill can last another 1-2 AA too. If mobs HP and damage has not been adjusted more, then w2w pulls are more viable.
Think about it in terms of eHP (Effective HP), not in terms of buff length.
TBN is a flat 25% shield, meaning in the 3-5 seconds it takes to break you take ZERO damage. Meanwhile, Camouflage might seem good but in reality its likely going to take those full 20 seconds to make up the same value...and even then, after 20 seconds many things would have died, thus reducing the incoming damage. This is why TBN is better..
I’m looking at it, and thinking more about stress on the healer. One or two GCDs of taking zero damage them right back to taking full damage means that time after it falls off is harder than 20 seconds of taking reduced damage.
Though I should say it’s probably more fair to compare TBN to Heart of Stone and Camouflage to Dark Mind in which case TBN is better than Heart of Stone and Camouflage better than Dark Mind when it comes to large pulls.
The biggest consideration for me is the healer, and the healer lvl, not the tank. I'm a tank main, and I took all 4 tanks to 80 before touching healers this expansion. I now have WHM to 80 and AST to 78. The biggest thing I can tell you is this: The healers are drastically different in terms of their abilities and tools at different levels.
Take WHM for instance, from lvl 71 to 80, they really only get one ability (at lvl 80) that helps them with single target healing. At lvl 70, they already have nearly every oGCD and instant cast single target heal in their arsenal. (72 DPS skills, 74 DPS skill, 76 AoE healing skill, 78 small Asylum buff, 80 temperance)
Then look at AST. From 71 to 80, they get some HIGHLY useful off GCD single target healing abilities. (72 DPS skills, 74 oGCD heal with a shield added too, 76 AoE healing tool, 78 additional oGCD single target heal stack, 80 strong CD. The skill picked up at 74 is massive, and I can tell you that AST feels SOOOOOO much better once you hit 74. The worst experience I had was doing Don Meg at 73 and the tank dying during the one double pull with the horse near the end. I popped everything I had, and once Lightspeed wore off, all I had were hard casts of benefic 2 and the regen from aspected benefic and it wasn't enough. That same pull once I hit 74 was a joke simply because of Celestial Intersection.
Pay attention to your healers and their levels, sometimes all it takes is one ability to make a big difference.