Dark Knight is playable, but BORING

[Quor]

I don't see how this is any different from how it was before only that TBN is stronger now and thus can be used to block better.

It's drastically different. In SB you wanted to avoid TBN usage because DA was almost always more of a gain per MP than TBN was. Hence, TBN was used almost exclusively to absorb incoming tank buster damage, instead of being something you used more or less on CD for what amounts to free mitigation on top of damage. Buster's are scripted to the point where you can safely manage your other CD's plus TBN and still have plenty of TBN uses on non-tanks to help with a variety of mechanics, and you're now actively incentivized to do so due to the feedback loop of popped TBN = free Edge/Flood. This, on top of the saved healer GCD's with TBN's 25% max hp value for everyone (instead of the 20 self/10 other it was in SB).