Tenacity

[Ultimatecalibur]

These % mitigation numbers youre quoting for ten arn't exactly right. Thats how much raw its adding however it has to interactive with the multiplicative buff stacking damage formula like everything else. For example of you had enough tenacity that it was adding a raw 3% passive mitiagtion, it would actually provide about 2.4% when stacking it multiplacatively with the passive 20% tanks get from the trait, and its value further decrease the more active mitigation you pop.

Uh... you are a bit wrong here. The diminishing returns you are describing here are only relative to the damage healers and dps would take. When comparing the damage taken between tanks, the 20% damage reduction from Tank Mastery is meaningless. A tankbuster that deals 150k damage without any additional mitigation from buffs or Tenacity is a 150k tankbuster on all 4 tanks.

The mitigation from Tenacity is always applied; so the mitigation that experiences diminishing returns is actually that from the cooldowns. The max Tenacity in 5.2 is 3845 at i500 which gives a .8975 damage taken multiplier.

The idea that I can stack a stat so high to nearly double the amount or more than the base amount that is on my gear but it only provide 2-3% extra damage reduction maybe is pitiful.

At ~i500 differences between minimum and max Tenacity should be pretty noticeable.

A tomestone set has 2028 Tenacity at base (.951 damage taken multiplier) which can be increased to 2954 Tenacity (.922 damage taken, a 3.1% decrease in damage taken) with melds and food.
Mixing Tomestone gear with Edenchoir gear for minimum Tenacity gives 580 Tenacity (.994 multiplier)
Mixing Tomestone gear with Edenchoir gear for max Tenacity gives 2872 Tenacity at base (.925 damage taken multiplier) which can be increase to 3845Tenacity (.8975 damage taken, a 3.0% decrease in damage taken) with melds and foods.

The difference between minimum and maximum mitigation is pretty big this tier with a 9.8% difference in damage taken.