I migrated away from 223/556 ar's.
I went with a 6.5 Grendel as my first, and now, starting a 6mm ARC build.
I've heard and read about how efficient these to are, to bullet weigh, powder capacity.
I coyote hunt, and my 223/556, AR's do just fine, but my thoughts of a heavier, wind bucking bullet, like my 243 uses, swayed me to the 6mm ARC.
The plus is, the states who allow semi auto centerfires for big game, but 22 calibers are not.
Enter a lightweight AR, shooting something like a 120 gr ballistic tip, or a hunting bullet of your choosing!

I just had to be different tho.