Wow, you have no idea what you are talking about. The highest boss armor valuse you see in endgame raiding is 7700, and every boss in hyjal has 6200. In a raid environment:
6200
-2600 (sunder x5)
-610 (farie fire
-800 (CoR)
=
2190
Gaining 300+ armor pen is a noticable difference against these bosses, as fully debuffed they are the same as a cloth wearer in pvp.
6200
-2600 (sunder x5)
-610 (farie fire
-800 (CoR)
=
2190
Gaining 300+ armor pen is a noticable difference against these bosses, as fully debuffed they are the same as a cloth wearer in pvp.