Millions of servicemen/women have been using AR rifles for decades without wannabe gadgets and gizmos like the BAD lever. They've done just fine.

Also, I love how people will waste money "upgrading" parts on their guns to "mil-spec". That term is so overused now it has almost no meaning, except to the two companies that actually have access to the military specifications for the M16/M4. That's right, two. The junk you buy from DPMS or Spike's is not "mil-spec".