Here's my biggest beef with PSA. You have no way of knowing what you actually receive vs what you think you ordered. They have a ton of variations in bolt carrier groups alone, not to mention barrels, etc. I have actually had friends place an order for a BCG and the item they received was completely different in appearance than what they saw on the site when placing the order. And you as the end user have no way of knowing what that bolt carrier group is made of or if it was tested or not. And this goes back to my point about a lack of consistency. You hit the nail on the head, with PSA, the end user IS their quality control department.99% of the time, when someone inquires about PSA, they get one of two answers. It's usually either "stay away" or "PSA is GtG". IMO, both are very poor answers. This is the most comprehensive PSA commentary I've seen. And I like PSA. With a few caveats.
One can end up with a very serviceable rifle from PSA, if they are willing to be their own QC department and like to tinker. I look at a PSA complete upper, for example, as a budget, loosely assembled parts kit that may well need to be "tweaked" a bit to get it just right. Other than a crooked FSB (if applicable) or a dogged-up chamber, there just isn't a whole lot else that can't be fixed by me. In that case, I'd have to deal with PSA's (very spotty) customer service.
I have tooling and like to tinker with guns as much as I like shooting. Is PSA for the non-mechanically inclined type who just wants to take their new rifle out of the box, clean it, shoot it and never have to otherwise pay attention to it? Probably not. Is the time vs money saved equation worth it to someone who doesn't just enjoy the process anyway? There again, probably not. For me though, it's just my cup of tea.
Of course, all the above is dependent upon taking PSA's published specs at face value. I do, and it's not because I think of PSA as a shining example of "corporate morality" or anything. It's that they're a big operation now and they have ruffled a lot of feathers in the AR industry, just by the fact that they have, more than anybody else, made cheaper AR options common to the masses. As a result, I think that they would have a lot to lose by falsely representing their components, as there would be plenty of competitors in the industry to call them out on it if that were the case.

