The armor cap (assuming Sotf) is Armour = 35880 armour to be capped at 75% reduction versus level 73 mobs. It is a bit lower for regular lvl 70 stuff, I think around 32k.
So, when you mouse over the defense rating on your character profile, and it gives you a reduction number, say 73%, is that all ONLY from armor, or is that from other things too, such as health, dodge, etc.?

How important is the armor cap? Is overall mitigation better?
For instance one piece of armor has 406 armor, but it only gets 406 mitigation points from 27 agility and 27 stam (27strenght, 21 Int) (Tree-Mender's belt)
Another piece of gear has 367 armor but gets 479 mitigation points from 28 agility, 30 stam, (29str, blue socket, red socket) Waistguard of the Great Beast.

So, one piece clearly has more armor which will help on the way to the armor cap. The other piece has more mitigation. The Great Beast belt is listed in several gear lists I have seen as the better belt of the two. (its also great for dps)

OK...i'll try to distill down into a question:
is the armor cap importnat to achieve? Or is the greatest amount of overall mitigation (armor plus dodge plus plus stam, etc) better to have even if you are not armor capped?

does that make sense?

Thanks,
OP

I get what you are saying.

1. Is the Overall armor cap something to strive for?
Yes and no. Yes because it helps you take less damage, but other forms of mitigation also are critical. I view it as important to aim for a blending of the three main forms of mitigation....

a) Armor mitigation - Important for PHYSICAL damage. The more you have the less you take, however at the trade off that you gain less Rage too.
b) Agility/dodge - Important because if you never got hit.... you never took damage (of course you never generated any rage too...) Plus if you crank up agility, you also get crit which means you generate more threat which makes your dps people much much happier.
c) HP - meaning you don't die when they hit you. Its one of our key forms of mitigation.

Basically you have to find a way to balance all three. If you hit 75% mitigatino due to armor, but you only have 15k hp (probably not even possible) then you've probably done something wrong. Its the balance of the three stats which makes it useful.

I've always gone with the following prioritization:
Def/Resilience to uncrittable > Stam > Armor >= Agility / dodge

Hitting the Armor cap in terms of mitigation is nice, but not a necessity ( and the # you see in your character pane is JUST physical damage mitigation from armor ), having a large health pool, is a necessity. Tanks die due to spike damage ( back to back crushing blows ), not to predictable steady damage. Druids are good at taking consistent damage. Warriors and paladins are more spiky since they will have strings of blocks, dodges and parries, and then take a string of hits.

Hope this helps :)

This coming from someone that has been a resto druid, a feral druid and a resto shaman.

OP's name is OP lol. is the armor cap importnat to achieve? No. Your goal is to build your tank stats congruently.

Some might disagree in that your first all-important goal should be uncrittability. I don't consider this genuine disagreement; you're not going to be wearing cloth with +int and +spirit because it has some +defense and +resilience. If you take a look at the tanking leather available to you, it's not only got a bunch of +defense but plenty armor and stamina as well.

Once you're uncrittable, you no longer have any use for more +defense or +resilience stats, so you can focus more on stamina and armor. This will happen more or less naturally as an uncrittable tank has access to better drops and quest rewards.

I've always gone with the following prioritization:
Def/Resilience to uncrittable > Stam > Armor >= Agility / dodge

I agree with the prioritization in general, but it becomes a little less clear when you begin to compare particular items. Let's assume that the uncrittable part is taken care of, the only consideration for def/res is whether or not losing, or trading an item will decrease them below the 415/112 levels needed.

Therefore, Stam becomes the #1 and armor #2.
If I compare possible upgrades using this priority, the results seem...intersting.
TreeMender Belt vs. WaistGuard of the Great Beast = Waistguard has more Stam, (but less armor), so Stam wins out. Upgrade
Heavy Clefthoof Boots(HCB) vs. Footwraps of Enchroachment = The HCB ends up with more Stam (using same gems) (but less armor) No Upgrade
Heavy Clefthoof Vest(HCV) vs.Vestments of Hibernation = HCV wins with Stam (but less armor) No Upgrade

For that matter- HCV vs. Breat Plate of Malorne = HCV wins with Stam (using same gems) (but has less armor) No Upgrade.

In Summary:
Assuming uncrittable...
Option 1
Stamina as priority #1 means that Heavy Clefthoof is king, only upgrade is the Waistguard. (-39 armor, +20Stam)
Option 2
Armor as priority #1 = Footwraps of Enchroachment, Vestments of Hibernation, and Treemender Belt. (also results in -75 Stam, +208armor)

Option 2 also has much more overall mitigation do to an increase in about +74 agility.

That is my dilemna. I am trying to tune better for Gruul, but I cant decide which way is better. According to a Stamina priority, I am okay, but according to all the calculators I can find, it seems that option 2 has better mitigation, although less Stamina.
What would you choose?