My experience with PSA has been 100%.
I've personally purchased five PSA uppers 10.5, 12", several 16" and an 18" upper. and most of them came with a lower parts kit. While the fit and finish is not top shelf, they all ran out of the box. There are little corners cut on like anodizing and I'm sure some of the materials used are not up to the same level as say KAC, Colt. and Daniel Defense.
The interesting thing to me is that Sig gets a ton of grief around here, and other forums, for their other products but gets a pass on the Rattler. I have no personal experience with the Rattler but it's good to see that others are happy with their purchase.