Just for reference, here are the tanking CD's listed with their comparative abilities from other tanks:

90 sec CD 20% DMG Reduction - Rampart (All Tanks)

120 sec CD 30% DMG Reduction - Sentinel (PLD), Vengeance (WAR), Shadow Wall (DRK), Nebula (GNB)

3rd Personal Mitigation Skill - ??? (PLD), Thrill of Battle (WAR), Dark Mind (DRK), Camouflage (GNB)

Short CD Personal Mitigation Skill - Shelltron (PLD), Raw Intuition (WAR), The Blackest Night (DRK), Heart of Stone (GNB)
Short CD Secondary Target Mitigation Skill - Intervention (PLD), Nascent Flash (WAR), The Blackest Night (DRK), Heart of Stone (GNB)

Self Heal - Clemency (PLD), Equilibrium (WAR), Abyssal Drain (DRK), Aurora (GNB)

Invulnerability Skill - Hallowed Ground (PLD), Holmgang (WAR), Living Dead (DRK), Superbolide (GNB)

Group Mitigation - Divine Veil(PLD), Shake it Off (WAR), Dark Missionary (DRK), Heart of Light (GNB)

Additional Utility - Passage of Arms/Cover (PLD), ??? (WAR), ??? (DRK), ??? (GNB)



I write all of this out because I like to see the whole picture when it comes to defensive abilities. Yes, the 20% and 30% mitigation abilities are basically the exact same, but the rest of the defensive kits are quite different, while also being fairly well balanced. Sure, there are some below average skills like Dark Mind, Abyssal Drain, and Living Dead (funnily enough all DRK abilities) that probably need to be looked at, but DRK also has arguably the best defensive skill in the game (The Blackest Night). IMO, the devs have done a really good job of balancing the tanks both offensively and defensively in this expansion. There are definitely some issues to be looked at, but their current design philosophy is pretty good.