American small arms design appears to be in the, 'techno-toilet'. If you want to go into battle carrying a camera, bring a Nikon. If you want a phone, well, you've already got one in your pocket. A battle rifle shoud be simple, rugged, reliable, easily re:chargeable, and reasonably accurate.
Look at the Israelis' experience: Israel ought to know; and they no longer use the M-14 or the FAL in any of their military units. During the six day war, many Israeli units complained that their FAL's were too slow, too cumbersome, and incapable of putting out accurate, sustained-fire bursts during the heat of battle.
IMO, the best military small arms are, still, entirely within the purview of the Russian military. I've heard rumors about the new Russian AN-94 battle rifle - it's supposed to be awesome! I understand that the new AN-94 fires twice at every pull of the trigger, and there's only a minimal recoil impulse. If it's, also, something like .260 calibre with short-cased, high-shouldered brass, all I can say is, 'Wow'! I'd love to try it.