I bought this in order to install a Franklin Armory binary trigger system in it, so I could try a binary trigger but still have the B&T OEM fire control group for reliability. I have not yet installed the BTS but I can say the aluminum B&T lower is exactly what you would expect. It is solidly-constructed and fits the B&T upper with the same tight tolerance as the OEM polymer lower. It has some minor cosmetic differences but is basically a metal version of the polymer lower, as expected. 5-stars. Thanks B&T USA.

The aluminum lower gives my GHM9 a much more expensive feel. My Mags drop free and they even machined a flared magwell into the lower.