Please keep in mine that meat labeled "Angus" or "Black Angus" should not be relied upon to be of better quality or tenderness. It's impossible to tell the breed of cattle of a carcass once the hide is removed, so I don't pay any attention, nor care, if it is or is not Angus. "Certified Black Angus" is probably actually Angus, but that's no guarantee of quality. It's just a brand name of a group of Angus cattle producers.
What is an indicator of probable tenderness is a USDA grade stamp of Select, Choice or Prime. If beef imported from the USA doesn't have any USDA stamp, it's ungraded and you are on your own. Look on the Internet and learn what each grade looks like and judge for yourself before plunking down extra money. Graded or not, there are differences that you can see and will taste. My opinion is that if a carcass would grade favorably, then the processor would have had it graded. These companies that don't grade their meat are good at marketing, but short on standards or objective data.
I have no clue about beef from other countries that might be imported. Beef produced in the DR that would grade Choice or better must be scarce, as I have never seen it yet for sale. And it would need to be aged!! The breeds of cattle that produce this quality of meat would not typically do well in this climate. I am told there are high elevation areas where British Breeds (Hereford, Angus, Shorthorn, etc) are raised. But they would have to be properly fed and the meat properly processed to be what most steak lovers are looking for in a "good steak".