I've had several Anderson lowers, and uppers, without problem and I'd not hesitate.
I've also had several PSA models and I will remain a customer. But there have been 2 problems:
First was a 20" 5.56 upper that would not keep all shots on an 8.5 x 11" sheet of paper once it got warm...PSA refunded without fuss.
Second was a PA-10 rifle, upper and lower (.308). It is heavy, nearly 10# with scope and mag. More important to me, the fit between the upper and lower was poor - a .050" gap at the rear mating areas, and lockup of upper/lower was loose.
The PA-10 rifle worked and was accurate, and for under $500 it was a great deal - but I wish the fit had been better.
Still, overall, I'd use either PSA or Anderson and see very little difference - both tend to be high quality and high value, maybe not always perfect.