I've burned through ~1000rds of the M193, and 500rds of the M855 with zero problems. I personally couldn't tell a difference between it and Federal XM193, other than the $100 I saved per case.
No worres about the "quality" of the PPI ammo. I have shot quite a lot of it in both pistol and rifle calibers. However, in several of the hunting rifle calibers I have shot, the velocities have definitely been on the slow side.
Its pretty good stuff. I think someone on AR-15.com or box of truth did detailed testing of the Privi andound that it met all of the specs and requirements of M193.
It's generally GTG stuff, although several report it to be a bit on the "weak and dirty" side. IIRC, the 55 grain pills were boat tailed, but with no cannelure.
If you're super unlucky, it's possible to run into tolerance stacking issues. Specifically, a chamber that's on the tight side of spec and this ammo, which is on the "big side", and you could get some feeding or even pressure issues.
The M855 gave lots of people problems around 2007-08, but I'm not sure if that's been corrected or not. It'd be wise to get a couple hundred to test before you went crazy on several cases, just to be sure.