I've used Anderson, Ruger, S&W, Bushmaster, PSA, and just completed a BCI. All end results have been the same as far as fit and function in the end. I really have no use for, nor see a reason for spending over $100 on a lower
Welcome to INGO Camaro123.
Milspec is NOT milspec unfortunately.
There's a few companies keeping their doors open with "BLEMS" and people wonder why they have problems and are just adding to the list of causes of the declining AR market.
Most of the AR stuff will work but when you get "hands on" on one of the poorly machined or horrible finish ones you'll regret not spending another $25 or so for a decent part.
I've recently became a fan of the Aero Precision stuff. Nice fit and finish. Very good prices and everything fit smooth as silk.