Plus all Waigu means is Japanese-cow. And per USDA regulations they can't have the bone in when they are imported due to foot and mouth disease.
So all waigu means with respect to good producers is it is a japanese breed.
Kobe is an unenforcable marketing term here in the us, in Japan it means something.
So waigu here in the states generally means great marbleing with a low fat melting point. Red/Black Angus generally means good marbleing. I have had my share of domestic beef and consistantly Black Angus is the best IMO.
Quick story - I had a buddy renting a house on a local Black Angus farm and every time I walked by the cows my mouth would water and palms got itchy. Needless to say it was really akward when I was cooking brisket and the cows were in the close field.
Good artical on kobe waigu -