I've seen those as well. Personally for me I'd still go .308. The lack of long-range trajectory is enough to turn me off. But if you look even closer at the advertised ballistics you are giving up an average of 800-900fps muzzle velocity with the same 125gr bullet when compared to a .308. That on top of the 30 Remington AR losing 500-700 ft/lbs of energy at 200yds when compared to a typical 165gr hunting bullet in a .308 puts the icing on the cake.
Comparrable to the 6.8 Remington SPC though.
Great advertising gimmick, but IMO unless you have to be the kid on the block with the shiny new toy, you can do much better with easier to find brass/ammo.