AC2200 vs AC3000 with ethernet backhaul

I am setting up wifi in a new house which has ethernet cabling installed.  Therefore I am planning on ethernet backhauling.  What I cannot figure out is if there is any advantage of purchasing the RBK50 with the AC3000 over the RBK40 with the AC2200 if I ethernet backhaul.  

On a slightly related note, using Costco for the Orbi, I can effectively get a 3 piece Orbi set up (AC3000 or AC2200) for the same price as a non-wifi router and a 2 piece Orbi setup on Amazon.  Any advice on going with the Orbi as a router and two sattelites versus a non-wifi router and two Orbi units as APs?

Thanks for taking the time to read my post and any assistance anyone is able to provide. 

BH