[{quoted}](name=A Blue Quaker,realm=OCE,application-id=3ErqAdtq,discussion-id=EOyfwKEJ,comment-id=0002,timestamp=2015-12-20T06:48:08.492+0000)
You forego 7% Magic Pen for it as well as Deathfire Touch. Not to mention it has a fairly sizable static cooldown. Then, if you go for Intelligence, you feel compelled to build 45% CDR instead of getting a more balanced build.
I'd much rather go down the Ferocity Mastery Tree, and have Cunning or even Resolve as my Secondary Tree.
The flat pen out scales percent pen until around level 14+(assuming they have players with 120+ resist). By then a lot of things have already decided the game.
Level 9, assuming half an mr item, is on average 45-55~ mr.
7% pen of 50 = 3.5 magic pen.
5 + 0.3 x 9 = 7.7 magic pen.
Thus the flat pen is greater than the percent pen by a long shot.