I looked back at my combat logs on Halfus and Valiona/Theralion, melee damage accounted for roughly 76-78% of all damage taken. I'd say that's a pretty good case for the stam/armor meta. As always though, there might be certain fights that would favor a spell damage reduction. You can configure Rawr to test out pretty much any scenario, take a look at the "Boss Handler" tab.

I'm looking for advice on trinkets. Rawr is currently giving me the armor trinkets from WotLK as being best-in-slot (Unidentifiable Organ and Petrified Twilight Scale). I don't mind if that's accurate, but it feels off.

The other question is deciding between the various stamina trinkets that proc tanking, or the agility trinkets. Also according to Rawr, Heroic Tia's Grace is the best mitigation trinket (ignoring the WotLK armor ones) and possibly the best overall trinket. Which seems accurate, but I'd like confirmation that everything is working correctly.

You can reforge that hit to dodge and the agi proc works out better than the straight dodge rating on the Crab. Mastery is only so-so as a stat so the proc with Crab isn't fantastic. All this assumes you're over the stamina soft cap for the fight you're gearing for of course.

Generally, if you are over the stamina soft cap, which is fairly easy for normal T11, you want to favour Agility highly. This makes Agi dps trinkets very attractive to bears. That said, you should have a selection of trinkets for different boss fights, i.e. stamina ones for heavy magic damage, armour ones for slow infrequent big melee hits and dodge/agility ones for frequent smaller melee hits and so on. So thinking in terms of BiS for trinkets isn't the best way to look at it really.

No it is not a bug, blizzard just did a very crappy job of itemizing armor trinkets so far given that they left those options in.

Because they can still get 2-3 shotted on heroic mode, and their DPS move out of fire faster so healers have more mana to spend on the tanks.

With that said, however, there is also the possibility that people might just not be reading theorycrafting and sticking to their old ways, I remember specifically back in Sunwell a lot of tanks refused to gem for agility until they saw a big difference on tanking M'uru adds.

Trinkets are still your best slots for optimizing stamina and agility, and you should keep multiple sets of those around. In regards to gemming, I still think agility is more optimal at the moment if you only have 1 set of tanking gear to play around.

Just as an example (hopefully it will be better than my previous post) here's the sort of damage I have encountered on the two heroic modes I have tried.

On Halfus heroic if you tank two of the drakes, each one hits for roughly 50-60k. Two of those do hurt. If your avoidance dependent setup fails, you can get two-shotted easily.

On Conclave of Wind heroic, after Anshal finishes casting Zephyr he receives a damage boost. Without a cooldown he hits for 160k damage, 80k with Survival Instincts. I can cooldown the entire duration but even then, I think all you can depend on is a single healer (possibly our tactic is wrong and you can spare at least one more). Everyone else should be at the Nezir platform soaking the aoe and healing it.

Hopefully that will answer your question why so many people (myself included) are going with stamina gearing instead of agility.

The problem with this argument is you are assuming the stamina dependent setup cannot fail. Also 50-60k hits will not 2-shot an agility-focused bear. Even in normals when I die with my more agility-focused setup, I find that I more often than not get overkilled by more than the amount of health I would get with everything regemmed/reenchanted for Stamina - and in reality the amount of health you get from gemming is a much lower percentage of your total health than it used to be in WOTLK.

You should be using Frenzied Regeneration and Barksin too, so you will be taking 64k damage, but with your 30% more hp and incoming heals it will feel just like you are taking 44.8k damage per hit. And the CDs will all be ready by the nex time you visit Anshal agai. At least they will be for normal, i doubt this would be different in heroic but I may be wrong.

For those who have yet to visit Chimaeron, he hits pretty hard, and the double attack soak tank has to be able to take a hit and still have >10k health (in case both attacks hit). They're frequent enough you can't rely on cooldowns (he casts it every 15 seconds, modulo other special abilities), and I saved my cooldowns for times when the healers weren't able to top me off. On normal I took some hits which were a bit over 130k. If swapping trinkets won't get you over the limit, then you start having to gem/enchant for stamina (obviously, armor is good, too).

This is a case where avoidance will only get you so far, and cannot be relied on (you can't just look at the average case). Optimally, of course, you stack just enough stamina to take a max hit plus a bit over 10k, and then stack avoidance to improve the odds of neither attack hitting (in which case healers don't have to top you off again, saving Massacre). However, until we know what a max hit is, it's probably better to err on the side of caution.

I think you must be quite severely undergeared if you have to gem/trinket for stamina to survive normal Chimaera's double attack. With my agility-focused gemming+enchanting, I'm still above 150k hp if I remove my Symbiotic Worm.

My point was that there are fights that have strict health requirements. I've only done Chimaeron on 10 man standard; presumably he hits harder on heroic and/or 25 man. I'm geared in half 346 half 359, and were I to gear for avoidance I'd have around 150k health, fully buffed, which I suspect would be a bit low for those environments.

Could anyone confirm this?

I just did Maloriak and I had a miss, and not only once, more like 4 or 5 times, even had a parry.

So is this Boss bugged or is that Statement just wrong?