I played with the ARX platform (Aka: "The Tactical Tuna") at SHOT 2015 and was hugely disappointed. On the whole, the rifle feels very "plastic" (which it is). More like a cheaply made toy than a serious piece of fighting equipment that I would stake my life on. That said, YMMV. I will be looking elsewhere for my newfound "black rifle" excitement. Specifically, the SIG MCX, which ought to be delivered this week. There is no comparison between the two. The SIG feels like a 6-lb carbine ought to feel - Solid. The ARX, not so much...
FWIW. I'm sure that others will weigh in with their impressions of the ARX family.