Assuming they are made of 7075T6, is there any real quality difference between mil spec stock mounting kits from different companies? BCM's kit is $20 more than PSA and both seem to be made of the same material. Any reason to choose the BCM over PSA? And any recommendations on other brands or specific places to order from? I'll probably be going with the H2 buffer so it's convenient that I can just add that to the BCM for $17 instead of buying one separate.