Understand that there's a different between USDA Prime vs the product S.R.F. sells. They developed a crossbreed of Wagyu and Black Angus cattle. I've tasted USDA Prime Black Angus as well as genuine Japanese Kobe (Wagyu) beef. There's a distinct flavor contrast. Both Japanese Wagyu and American Kobe Style Beef has a more pronounced "beef" flavor and a "creamy" texture that's different.
USDA Prime doesn't specify a specific breed, only a higher level of marbling vs Choice (which in itself has a wide variance of marbling) American Style Kobe/Wagyu marbling is greater than USDA Prime.