I installed centric posiquiet pads and their higher end rotors and I must say, they're the worst pads I've ever installed. The grip is ok the pads look fine before install, all they do is squeal. Here's a video :

 

That's almost as bad as my Project Mu HC+800s, I've tried chamfering and greasing the **** outta everything but it hasn't helped. Maybe worth a try for you though.

 

I've tried two different brake lubricants. Even lubed under the shims. I think there is a piece of metal too large in the pad that's causing it to chew into the rotor.

Needless to say I'll be installing my stock pads again since the only reason I didn't brakes was because had a vibration. Should have just done rotors and called it a day.

 

Are you using the OEM stock shims? If not, that is likely the cause of the squealing (they are angled for a reason)

Anyway, just a thought. I doubt that its due to the pads unless they were a race compound

See below: