From wow.incgamers.com

Statistics

Talent Improvements

The talents below affect Fel Armor in the following ways:

Talent: Demonic Aegis
Effect: Increases effectiveness of Demon Armor and Fel Armor.
Statistics: Rank 1 = +10%, Rank 2 = +20%, Rank 3 = +30%.

Threat Level

Please insert details of level of threat generated by Fel Armor.

Uses in PvP

Please feel free to add a bullet list of uses within PvP or editorial if you have more to say. What use is it against other builds, what skills can it be used to counteract or prevent. What skills does it work well in combination with.

Uses in PvE

Please feel free to add a bullet list of uses within PvE or editorial if you have more to say. What skills does it work well in combination with. Which creatures/bosses in particular is it useful against.