There are a lot higher end AR-10s than mine. I will say it is a tack driver, nearly as accurate out to 300 yards as my two favorite bolt guns. Also, it has a flat top, so you can scope it. The FN-FAL has no provision for a scope.
The thing is FN makes a bunch of our US military weapons: the squad auto, the bigger machine gun, crew fired weapons. I think they have more ability to create a 21st century fighting rifle that is superiour than the more-or-less civilian oriented companies like DPMS, Bushmaster and Armalite.
The Knights Armament AR-10 is probably the best, and has been developed for the Navy.
As for Knight's AR-10 being the best, I take it you are referring to their Stoner SR-25, which is indeed 'best of breed'. LMT now makes a .308 version of their monolithic rail platform that I hear is also an excellent choice.