Well, from what I have seen of the rifle. It appears that when it has it's optical sight system it doesn't have back-up iron sights. The rifle does have iron sights but they're removable.
Its the biggest thing right now in the arms market. Make a rifle with no factory sight. Rail only. Sig Sauer, S&W, Bushmaster, FN Herstal, Heckler & Koch. They're all doign it.
I'll stick with the system i have now. Permanent front sight, lip up rear sight, Eo-tech reflex sight.
My Eco-tech is the main sight on my rifle. Well built, tough as nails, and really makes it easy to engage a target. But it can run out of battery power or simply break. So I still have the factory front sight still on my AR-15 and I have a flip up rear sight.
I think this is the best rifle ever built. Beats all of those new age plastic rifles like the H&K G36 or British L85 Bull-pup.
Only thing that is better than what I have now is the M1 Garand.