Stuff on AR15.com tends to get blown way out of proportion. You'd think from the tone of some members there, your rifle would turn into a neutron bomb and destroy life as we know it if you used an optic outside of an ACOG or Aimpoint.
You're exaggerating worse than the few vocal doofuses do on ARFcom. For every thread where someone puts down an ACOG or Aimpoint, there's just as many singing the praises of a lesser glass. The ammo threads are limited to first hand reports, and are usually fairly representative of people's experiences with a given brand. I trust ARFcom's collective opinion more than this site, given the dedication to the round there.
That said, look at one of the most widely derided .223 ammo out there, Wolf. I can honestly say I've NEVER seen a case-head separation, blown up gun or KB due to it, and I've also never seen any systemic reports of bad or malformed rounds. It sticks in chambers if they're dirty, but that's not a ruined gun, or an injured shooter.
PD is seconds, and seconds are rounds that have failed QC in some way. In the case of PD, they are Grade 3 rounds, or the bottom of the barrel for Lake City's quality. It's not surprising, nor should it shock anyone that it's not the best ammo money can buy.
Here's AR15's survey data on the various brands, where PD ranks BELOW Wolf.
http://www.ar15.com/content/page.html?id=210
Here's a thread with some good information about its origins. I suggest you read it, before using or buying PD.
http://www.ar15.com/forums/topic.html?b=3&f=16&t=292762
