I have a EOTech Flip to side 4x for my shorty to use with my XPS, but with a 16” and longer barrel I use this
http://www.leupold.com/tactical/scopes/vx-r-patrol/ I use this to I can reach out and touch someone, plus I also use it for 3gun on my DPMS rifle. I don’t see the need for anything over 4x with a EOTech you know that center dot is covering more then you need it to a 400 meters. Now don’t get me wrong I can hit stuff at 700 all day with the 4x on but I can’t see the splash.