Dec 27th 2008 9:53PM Mensrea is right.
This article is horrible. Sunder armor is a given in any PVE situation. If you want to decide if ArP is "garbage" given your current gear, then you need to do a real model with you current gear and determine your personal AEP values for the stats in question.
I can't even fathom how the author's original argument was supposed to work. In my mind it becomes paraphrased thus: "Look at how good armor penetration would be in this imaginary world, and now look at how shitty reality compares... we therefore conclude armor penetration sucks."