DA alpha

My DA tank just hit 50 last week. I haven't really plotted out incarnates yet, but I'm starting to turn my attention to alpha. It seems one of the new ones - Agility, is a clear winner. It buffs End Mod, Rch and Def, and adds movement speed as a tertiary on the right tree.

I don't have endurance problems, per se. I can last a fairly long time in a fight without outside recovery buffs, but not indefinitely. Because I sought typed +Def buffs, I have very little global recharge, so having more from alpha would be welcome. Lastly the Def buff takes me from a smidge below soft-cap for s/l/e/n to a smidge above. More precisely, this def buff will allow me to unslot the Glad Armor proc I'd rather not use.

Anyone have a convincing argument that "No, Agilty pales compared to..." and what it is that is better for Dark Armor (Armour if you prefer)?

What you've outlined there are fairly good arguments. I personally like the Cardiac alpha for mine and that's more for the Resistance than for the Endurance Reduction (although that helps too). My tanker is Dark/Elec and all my Defense comes from either pool powers or IOs (well, and Shadow Cloak). If you're playing a secondary that has a Defense power in it, like Martial Arts, then I'd say Agility is a clear winner.

I've also been considering Resilient for much the same reasons as Cardiac, but I'm just not convinced the extra Resistance would be worth the loss of the Endurance Reduction and the secondary effects just don't interest me.

In short, I think for a DA tank the best choices are probably Cardiac Core or Agility Core. You might be able to make a case for Resilient as well, but I think playstyle and what you have for your secondary and your ancillary are going to be major factors here.

Personally, I would probably lean towards Agility too. But if you are really struggling with recharge, Spiritual might be the way to go. A Tier 4 core, you'll get 45% instead of 33% (So you'll get 8 % more ED protected recharge). Plus your healing (Health, Dark Regeneration, and Soul Transfer will all benefit) gets 33% enhancement. And your Stuns (Did you take oppressive gloom?) get 33% enhancement. So... if you're not hurting with Endurance recovery and your defense is shored up nicely, then you might like spiritual because it gives you 8-9% more recharge to all your powers and you will have stronger healing and stuns.

I planned on going Cardiac on all my DA Tanks, but now I'm going Resilient for just that much more resistance.