My preferences are:
EOTECH 552 mounted on a carrying handle.
1. I'm not a big fan of the rail system with a flip up sight.
a) A lot of people forget to flip the rear sight up.
b) The optics are mounted so far back...that you can't flip the rear sight if need be.
c) There is nothing to protect the rear sight from being knocked out of alignment.
d) Watch how much unnecessary shit people mount on the weapon...like it's going to make them a better shooter.
Just my .01 cents