JMR40, not referring to brass, but safety position. I find when shooting lefty for fun, its easier to operate the safety on a mini than AR, which was obviously designed with righties in mind.
Huhwhat? The AR platform is one of the most lefty-friendly platforms I can think of. The charging handle is ambidextrous, an ambi safty is easy to install, and the brass deflector keeps brass out of the face. I'm pretty sure there are options out their to add an ambi mag release as well.