Tenacity

[Deceptus]

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.

And that is essentially a permanent Reprisal debuff on the mobs.