This is not the whole story. Black Angus now come in designer sizes. "LowLine" (tm?) Black Angus are some of our smallest cattle, and some of the modern extreme types are closing in on the size of Holsteins.
The American Angus Assn (of which I am an inactive life member) is, perhaps, the best run pure breed association ever. Starting with a great product, and with better marketing, they have taken the Black Angus from an "also ran" to the most important beef breed in the USA.
The Hereford and Shorthorn associations represent good cattle, but for whatever reason the Angus guys have left them in the dust. The CAB program is just one of the innovations that have made Angus more profitable for farmers.
Is CAB worth the extra money? Yes. Because it is better? I don’t know. It is worth more because shoppers are willing to pay more.
Just my opinion.