Just looks and feel. Nothing fundamental quality wise. Rra stuff is pretty top notch. Its not like buying a dpms where there are drastic levels of quality.
The difference in price is likely one little feature is slightly more pricey to produce than its counterpart. But both will be equal in quality.
I've got two rra guns and a bcm. The rra are my target range hunting guns. The bcm is the one I'll grab when shtf starts up.
"Gun control: The theory that a woman found dead in an alley, raped and strangled with her panty hose, is somehow morally superior to a woman explaining to police how her attacker got that fatal bullet wound." — L. Neil Smith
The problem with being stupid is you cannot simply decide to stop doing dumb things...
"I crapped my pants to avoid the draft!!" -Ted Nugent