About the only 'issue' (if you can even call it that ;^) that I've ever had with Anderson lowers involved the mag well - a Hahn 9mm mag adapter would not fit. That was likely due to the mag well being just slightly too rounded in the corners, to accept the sharp-cornered Hahn product. A PSA 9mm adapter fit the Anderson perfectly, as did a couple of other adapters I tried, from different manufacturers.
A lot of guys jump on the band wagon for a particular brand (like Colt), and criticize anything without their favorite label on it. I knew a gun shop owner a few years ago, who was a big Stag Arms fan. In reality, "the proof is in the pudding" - does it work, or not? In my experience, Anderson lowers work.
I wouldn't trade my Andy lower for a Colt, nor a H&R, an FN nor a Bushmaster.
There's a good article available, over at Lucky Gunner, that includes a little info (related to a couple of Bushmaster ARs) about why it's unwise to put too much trust in a 'big-name label':
https://www.luckygunner.com/labs/brass-vs-steel-cased-ammo/
I’m amazed at what people will pay for a rollmark. A friend paid big bucks for a Rock River Arms. It was all that was available during a run on guns. I’ve only ever seen one gun with more slop between upper and lower, and that was an old cast Olympic Arms that someone dragged out and slapped a $1000 price tag on during the same run, I believe.