Armor Pen

I cant help seeing more and more high end players, mostly rogues.
Using armor penitration as their main gem/enchant stat..

I cant really get the math to work, but obviosly they know something i do not.


The good thing with armor penitration is that it scales well with your other stats as its a % gain in damage.
The bad thing is, that you need quite the attackpower/hit/crit rating for it to be benefitial.

200attackp = X fixed amount of dps boost.
200armorp = X% boost.

Now, what i want of you brainiacs is a tip or a calculation on when armor penitration starts to really give you a boost comparred to what +agility or +attackpower gems would do.

//Eonuz

Perhaps the following link will help you a little even if he talks about druid cats.

http://altosis.blogspot.com/2009/07/31-cat-druid-armor-penetration-murders.html