To answer the main question, no, my 5.56 guns would be choice number one. Lighter, lighter load out with more rounds, much more common to pick up off the ground. .308AR is a nice weapon but it’s much heavier, loaded mags are twice as heavy carrying 10 rds less each mag at least.
think…. If I’m carrying this several days in a row, out on the field, or running with it, which would I rather have? As usual Tom hit the nail on the head with his post on firefights… it’s hectic, and all plans swirl down the shitter cause everything goes sideways. High pressure brings you down to your lowest level of training. You can have a MK19 but if you haven’t trained you are as useless as a snow shovel in the desert