Having had a few of them rascals ,for a few yrs,I'll take a shot.
Never met a serious taster that could tell a pure Angus from a chicken thigh.
If you want your cows labeled "angus",it ain't hard.
The state assoc.used to charge $10,and you got listed.
The national assoc. used to charge $25 and you got a fence tag and a bumper sticker.
Now,some of them get real strict and post that the "mama cow" should be 10% red,or black,Angus.
The rest could be dairy cow,Longhorn,Easter Bunny,etc.
The attraction of Angus,in Scotland,was they were little/gentle/managable.
They were surefooted and could walk around on slick,iced rocks.
They had black face,so they didn't get pinkeye and go blind,like some whiteface.
Whiteface were expensive to treat,went blind,you sold them at auction for hamburger.
Angus could thrive in wet,cold,rugged terrain and live on moss/mold,etc.
Like Smokin' said,at least CAB are supposed to be in the better part of choice and I don't remember anybody claiming they were purebred angus.
Our sam's carried "angus packers" for awhile and other than being small,I couldn't see any difference.
The were the same price as Excel.
Now Publix and the supermakets charge a premium for "angus'.
Like Smokin' says,some have a bigger ad budget than others and black Canyon does have a better web page.