Three uppers and a lower so far - zero issues.
OP, remember that the squeaky wheel gets the attention. If you buy a product from a retailer and it shows up looking perfect, how likely are you to go post on the internet about it with pictures and a lengthy writeup? Not very; it's what you expected. If, however, you get a lemon how likely are you to? Far more.
Take it all with a grain of salt. The AR world is a lot like a bunch of divas bashing companies and people. As an earlier poster said, one day it's Anderson, the next it's PSA, and the next it's BCM. I personally have had three utterly flawless complete uppers and the same in my lower. They are my go to when considering AR components.