I've had 1 Anderson lower and used their upgraded LPK. Seemed mil spec. And I'm happy with it. My friends like theirs. But definitely not in the class of the benchmark tier manufacturers.
Four years ago, I bought two Anderson PCC rifles. They take Glock mags and have shot everything put through them including reloads without any issues. The only mod made to them has been to do some polishing on the triggers and installed JP Enterprises trigger springs. In the 4 years of use, and many thousands of rounds through each of them, they have been flawless. I hear all the trash talk about Anderson. But my results have been pretty good.