I've looked around in the various tanking threads, but am still lost. The DPS threads have stat values for Strength / Armour Penetration, etc : AP. Are there any numbers for tanks for those stats, and threat, mitigation, etc?
It is hard to create stat weights for tanks, since some of it is personal preference. In general, you want the highest item level "tank" piece in each slot. When you have choices of the same item level, then you must decide what stats you prefer (I like to get the tanking set bonuses, while others don't care for it).
Generally Suno makes a list of the "best" tanking gear if you have trouble deciding which ones to go for when their are choices.
Regarding threat strictly, one can assume stat weighting is similar to the tree used. e.g. Blood DPS stats for threat in blood tanking. However a better job could be done if one used the simulator on the actual tanking talents.
I just have a question regarding Sigil of Virulence for DW Frost (i'm currently running 3/53/15).
In the BiS-thread the SoV is now mentioned as BiS for all specs in the OP, but I can't find any posts to where this has been proven better than Awareness.
I do know that SoV is better for AoE-fights like Freya, but I was under the assumption that SoA still was a bit better than SoV in single target fights?
If you take t9 BiS set pieces you either off set chest or helm - considering more builds prefer to off set the helm I used Shoulders, Chest, Gloves and Legs for calcs. For the purpose of this 'theorycraft' we will consider t8 4pc and t9 2pc equal (even though t9 2pc beats t8 4pc for every spec), so we are comparing dropping t8 2pc for t9 4pc without the set bonus (ie pure itemization).
Going from t8 to t9 nets the following:
82 Armor Pen
The t8 2p is worth ~120 ap to UH, ~90 ap to DW Frost, and ~70 ap to Blood, so for t9 to out perform t8 2p without calculating the t9 4p you would have to beat...
Unholy - 287 ap
Frost - 326 ap
Blood - 300 ap
Now, the bonuses above total...
Unholy - 633.38 (gain of 346.38)
Frost - 697.24 (gain of 371.24)
Blood - 749.09 (gain of 449.09)
So, yes, regardless of the set bonus functioning correctly at the current time the t9 4pc ilvl 245 set (shoulder / chest / gloves / legs) are dominant over t8. Once they fix the bonus (assuming it isn't intended) the values will go up even more. As for the weights used I used the 3/13/55 2h UH, my personal 3/51/17 frost weights through multiple 1,000 hour sims in the simulator, and an updated version of my personal blood stat weights (factoring in fixed arm pen value) as the values. I can post those weights if you would like to do your own testing (different off pieces, like plated leggings of ruination, etc.).
The end result is, however, that t9 is clearly dominant despite the 4pc being broken, so it is very much so worth the investment.
You would need to do your own math then. The stat weights are in Zerack's Gear Optimizer program, you can go to Wowhead to compare the two sets stats and see if they are still a bonus for you on an individual level (which pieces you intend to upgrade, what 239 loot you may have that is better than the 232 loot, etc).
You simply take the t8 2pc bonus, and then add whatever stats the t8 has over the 232 t9 (should just be expertise and haste), and then use that as your base value that the other set needs to exceed to be an upgrade. Then you take the bonus t9 provides over t8 and muliply those by the specific values listed in the optimizer and subtract the initial value you achieved from the t8 2pc and t8 raw bonus to see the effective attack power you receive from the upgrade (and without 239 loot it should be a very solid upgrade).
edit: Also - I forgot to mention any socket differences between the two sets and didn't factor having them socketed (they both have 6 sockets - t8 has 1 red, 1 yellow, 4 blues and t9 has 3 red, 2 yellow, 1 blue - in the end from a raw itemization format on sockets the t9 should be a bonus anyways, especially considering the 4pc mentioned above all have str socket bonuses on t9).
While we're on the topic of 4 pc, is anyone familiar with a weight for the four piece bonus for the 0/17/54 dual weild DC spam build? Crit diseases seem great since our crit is usually high and our disesases strong, but they clip extremely often due to IUP and the nature of the spec to the point that each disease is only like 5% of my damage. Despite the increase in stats, I have to wonder if it's worth losing the 2 pc t8 (since dc is my main attack), especially if my diseases are just going to clip so much. Unfortunately we don't have set bonus numbers in the dw thread op for this spec. :x
I guess this question could be answered by Asphyxia above if it's true that his conversion of the 2pc t8 bonus to AP for unholy holds true for a build which spams DC mich more than your average UH 2H build.