The m14 was a based upon the Garand and George Patton said the Garand was the greatest battle rifle ever designed.
Troops in Vietnam complained, however, that the 308 round was heavier than the 5.56 and thus couldn't carry as many mags of 308 as they could mags of 5.56. Also, the 308 was more difficult to control in full auto especially when so many troops adopted the spray and pray technique.
I have a Garand and a MIA national match in my defensive armament. Also a Ruger .223 Ranch Rifle and an SKS. I’m ready no matter what.