Jan 1st 2009 9:09PM Everyone who reads the main article should immediately have to read Thernderhoof's post. He is deadset right. The fact is on the surface arpen may appear to be crap, and in certain circumstances it is less effective than others, but for raid bosses, even those who have been affected by a sunder, arpen will still most always come out on top of crit, and other stats too depending on spec, moreso after the hunter nerf coming in 3.08. Without going into the mathematical mechanics of how arpen works, consider these points:
1. crit stacks linearly, it wont gain as you stack. Arpen stacks, so more arpen = better dps boost.
2. the best way to increase a fractions value isn't to increase the value of the numerator, it is to decrease the denominator by the same amount. take 4/5 as a fraction, increase the numerator by 25% and you get 5/5, or 1. Decrease the denominator and you get 4/3.75 ~1.067. Arpen functions by reducing the denominator, so comparing straight numbers wont always tell the full story.
3. arpen affects NET dps, crit will only increase base dps, so if you reduce a mobs armour enough to boost dps by 1% with pen you will be doing more damage than if you gain 1% crit chance
4. at 20% armour pen (easy to reach, with the current gear) net DPS is increased by 11.02% on a boss with no sunders, or 8.2% on a sundered boss. By comparison, crit chance with 308 rating (equal to the arpen, assuming they have the same weighting in terms of item budget...they certainly do with gems) is 6.71% crit chance. As noted above, that is NOT a 6.71% DPS increase, even with the effect boosted by mortal shots, gfft etc net DPS wont break 7%.
5. with the upcoming nerf to steady shot, AP and to a lesser extent (but still a significant one) agility are going to be less effective. For BM hunters haste is already not very useful, only boosting auto-shot speeds. Which leaves hit (easily capped), crit and armour pen. Most gear comes with good ap/agi already, so many hunters will look to stack mainly crit or arpen.
Summing up, arpen is terrific, in the right circumstances. People need to look at it's application, not the raw numbers. The article is very misleading because it does not delve deep enough or show enough critical thinking about particular mobs and how arpen may boost damage. If you aren't a raider, then ok, arpen may not be for you. If you run lots of 5 mans with a prot pally/druid, get into it, you wont be dissappointed. If you are a raider, have 2 sets of gear, one with 6% hit that stacks crit and a boss set with 8% hit and arpen. Simple.