now one thing that we have discussed in the past is that the rings, trinkets, and necks on that list are using the armor value of armor that gets modified by bear form etc. How good really is that trinket. I want to try switching but I really just cannot bring myself to do it. hell I vendored defenders code the day the armor nerf went live. I still am one of the largest armor whores I know, hell up until a month ago i still used origin of nightmares but with dps in full 25 man hard mode dps gear I just could not put off anymore i needed the extra threat armor be damned. But even still 162 stam for 1800 unmodified armor... I really don't know.
The list he's referring to is the bear itemization weighings at wowhead, which does use the value of armor for both leather and nonleather. For the most part it ends up working well anyway, mostly because items with armor have a lot of it, and items without it don't (and the stats they do have in place of it aren't that valuable). Which, if you looked at the bear gear guide for ToC...doesn't actually use that weighing. It uses Rawr's. But it doesn't really matter, because all that matters is this:
How good is armor?
Armor's a lot tougher to evaluate than stamina is. Stamina never changes, so we know exactly how much we're getting. For each point of stamina on gear, bears get about 15 health after all raid buffs are factored in. But armor? Armor depends on the level of the attacker, how much you have beforehand, how much you're going to have, how hard the attack is...it's really nebulous.
And most people don't work well with nebulous.
Okay, I'm here today to tell you: armor is AWESOME. Armor is the only stat that improves both effective health (how much total damage you can take) and mitigation (how much damage you take per hit). Armor does have its flaws though, and I'll show you some of them. I can do some graphs and show you how its diminishing returns don't matter since the time to live for armor is a linear function, but that doesn't tell you anything.
So instead, I'll point out to you how much damage you can take and how much armor helps in each specific case. I'll be comparing two trinkets: Glyph of Indomitability and Juggernaut's Vitality. (The awesome version, in case you were wondering).
Glyph is essentially Defender's Code's bigger brother. On a side note, I want you to think about how insane Glyph would have been if the armor change hadn't happened early on. That's right - over 8000 armor from it alone. Yeesh. It gives 1792 armor that isn't multiplied by anything other than the metagem.
Juggernaut's Vitality is 216 stamina, which translates to the absurd 3200 health. Yep, all by itself.
3200 health is a lot. So is 1792 armor. Which is better?
Ultimately you have to think about it. Having tools handy is good, but there's no one set that will be optimal for all situations. When you've got a nail, use a hammer. When you've got a screw, use a screwdriver.
Okay, case study one: Algalon-25. Algalon isn't the best fight for a bear relative to almost any other class, since he attacks so often. With higher avoidance DKs can get more reasonable streaks. With block, paladins and warriors can mitigate more damage. But you still may be called to do this fight, so let's see how you can do. We're going to start with the base armor of 32000 - a nice, round number after buffs and whatnot. Algalon can do a 35,000 damage quantum strike, a 10,000 phase punch (not apparently physical), and more importantly can do a 60,000 main hand and a 35,000 offhand hit.
Those main hand and offhand? Can happen in a second. In the same second.
How does armor help with them?
In the 32,000 armor case, here's what it does. I'm assuming full raid buffs on the bear, meaning PotP is up, inspiration is up and grace is up. The total mitigation would be .741 in this case, meaning you only take 25.9% of all damage. (1*armor mod*potp mod*grace mod * inspiration mod)
MH: 15561 damage average
OH: 9077 damage average
Quantum: 9077 damage average
MH: 15004 damage
Assuming you get hit by both a MH and OH, you will have stopped 880 extra damage using glyph over juggernaut. However - and here's the important thing - in order for this to make you actually live when you wouldn't have, you would need to take 4 MH+OH in a row to mitigate the same amount of damage that Juggernaut can stop.
Also reasonably, you need to survive MH+OH twice, which is just below 50k health. Any more than that and it's nice but not essential. Any less and you're playing with fire. With the glyph though, that maximum only is 47.5k.
That doesn't take into account another factor: endurance. The theory of effective health assumes infinite mana and assumes healers will always heal you to full, but the problem is that...it's not true. Tank death often happens because a tank hasn't been topped off and is sitting at a low state until the tank gets lucky with avoidance or a healer blows a big heal. In those situations, armor is far more useful than stamina; it means you don't get in those situations as often (because you've taken less damage) and you don't need as much health to survive (because you'll mitigate it).
Which do you think is better for Algalon? I used Defender's code for a while along with elixirs of armor and pots of indestructibility. And it was okay, and worked better for me than the pure stamina situation. In the stamina situation I survived at 2k once, but I also died more often due to the healers simply getting unlucky and not being able to catch up. Armor helped a lot more in that regard. It turned out, sadly, that avoidance trumped both of these considerations, and bears just don't have the avoidance that other tanks do.
How about something a bit more up a bear's alley: Heroic Beasts. Or more importantly, Gormok. Gormok, as the fight continues, hits for absurd amounts of damage. Really absurd. The normal attack can be as high as 100,000 damage, and impales can be as high as 120,000. Then there's the bleed stacks the impales put up and the stomp, which is another 40k hit. How does armor deal with this:
25935 normal, 31122 impale, 10374 stomp
25007 normal, 30009 impale, 10003 stomp
Differences: 927 normal, 1113 impale, 371 stomp
Those are kinda huge.
And yet they still might not make up for the worst case scenario - where a normal hit + an impale at the highest amount of damage is just too much to take - and that worst case is an impale + a normal attack within a second. In that case, you need to have 57k health to survive the worst situation and 55k health to survive with a glyph. Even if you're well-geared, those are hard to meet; the best bet there is another cooldown use and prayer.
Again - armor here helps tremendously with healers being able to catch up. Over time you'll take significantly less overall damage and if you're down, are more likely to survive. But that worst case scenario is likely better dealt with via stamina, especially given the amount of bleed damage you'll be taking. My personal strategy was to go with Defender's Code and Heart of Iron, so that I could use both trinkets for another mini-cooldown early on to help out. There was at least one wipe that was caused by me taking just over enough damage to die this way, though, so I'll be going to double stamina trinkets - especially since I just got the awesome version of Juggernaut's vitality.
So in two cases where there is heavy physical damage, stamina still is competitive and/or wins out and the Glyph doesn't. Why do I have it ranked so highly?
Well, part of it is Rawr's ranking system. Rawr ranks based on average damage taken and survivability/time to live, and honestly it's somewhat flawed for these kinds of fights. You don't often care about average time to live; you're not sitting there for multiple seconds while your healers get their thumbs out of their asses and remember that you're tanking. It's more often the case that you care about the worst case scenario in a short period of time and whether you can survive it at all. That's not average damage, that's burst damage. Fortunately, Rawr is coming up with a solution to that.
Rawr likes Glyph (and DM:G) because they average to less damage and gives avoidance which will over time reduce average damage. That might not be that useful to you, depending.
That isn't to say avoidance doesn't have its place; like I said above, avoidance was much better overall for our attempts at Algalon due to his speed of attacking; it meant our healers weren't put into horrible positions and if a healer had to move because of smash, it wouldn't be the end. But it does mean that it also isn't useful everywhere.
So...okay, you say. Armor isn't the best thing ever, and you get that - but is there ever a time where it is awesome and way more awesome than health?
Yep. Heroic Anub'arak. On this, health is a detriment as it heals the boss while doing more damage to you as a percentage. That Juggernaut's Vitality heals Anub'arak by itself for 600 health every second, while dealing you 600 damage a second (before resists, of course). Meanwhile he hits like a truck, and he can hit you with a stun and then normal attacks that hit even harder. The only thing you can do here is use armor. Armor does not improve leeching, it does work when stunned, and does not rely on any RNG components. In this situation, Glyph is absolutely the best trinket you can get; reducing (on average) 800-900 damage a hit is much better than having a 3k buffer that also heals the boss for 600 and does you 600 more damage.
So it's really, really awesome there. But I don't know if it's worth spending 50 emblems on it over a T9 piece.
The really long and short of it is this: get health when you need to make sure you can survive the absolute worst case situation, as health scales far more quickly for a druid than armor does any more. If you know you can survive the worst case situation reasonably, health is much less useful and you should either go for more avoidance (which will help overall damage intake on average) or more armor (which will also help damage intake, but more reliably) depending on what the encounter is like. Finally, stamina does something that armor and avoidance do not: it helps with magical soaking. If the fight has a lot of magic damage (twin valks, Jaraxxus, Mimiron) stamina is going to be better than armor.
Again, ultimately you have to think about it. Having tools handy is good, but there's no one set that will be optimal for all situations. When you've got a nail, use a hammer. When you've got a screw, use a screwdriver.