Trinket question, EH/AV or AV/EH

Picked up the Fervor of the Frostborn yesterday from Faction Champions10, and it's kind of derailed my Triumph shopping list. It is pretty much the reverse of the Glyph of Indomitability, and I want to know which one is better in terms of hard-hitting bosses (let's use XT-hard and Thorim-hard as examples here). One is an EH trinket with an avoidance on-use, the other is an avoidance trinket with EH on use - on say 6 Thorim stacks, which will end up saving more damage?

Thanks!

From first look I don't like the Fervor.

1. You decide to click the effect. The 20 second timer starts ticking....
2. You have to take a normal (i.e. no extra mitigation) hit. THEN you gain 1265 armor...
3. You have to take another hit. Then you gain another 1265 armor...
4. Repeat, if the boss hits you often enough, three more times. (I assume blocked hits count as well, but meh.)
5. The whole stack falls off, and you have to wait 1:40 to use it again.

I'd rather have the permanent armor from Glyph.

Agreed. As far as I can tell, for slow-swingers like most bosses, it will take a long time to build up stacks, which works against you. I also don't like that it's a Use effect. I'd like to see some parses and math on this, but my napkin math a while back seemed to show that the proc on the Black Heart gave more average armor than this trinket, which seems a little backwards.

Thanks - I'll keep that in mind.

A follow-up question: is the higher passive dodge on this trinket better over time than the good ol' Valor Medal, or is the on-demand burst of dodge from the Valor Medal of the First War more desirable for predictable bursts of pain?