MikeGunz, that video explains the mil-spec, which is of decent quality. However, there are several glaring falacies in that video as well. If one wants a quality M4gery, sure, a Colt and a BCM are good options, but they are hardly at the top of the class across the board. The M4 fanboys only real success is holding back the masses from realizing what some of the best AR-15s are really capable of.
IF I ever needed a top drawer M4, I'd be calling up Noveske anyway. Yeah, they are a title sponsor of my match and I am personal friends with their Pro Shooters, but they do make the best hard use M4 style rifles on the market.