I think Tim is right, there is a lot of fuss, for what I do not really understand. The American Wagyu I have bought, has never been identified as coming from Japan. I would like to try the Aussie stuff, as my understanding is that it is better than the American Wagyu.
I will note though, that the American Wagyu was intended for export to Japan originally and that the original stock developed in Oregon was for that purpose, same as Australia. But, politics raised it's ugly head and we have mutual embargoes between Japan and the U.S. preventing beef from crossing the Pacific. Ironically, this does not exist for pork, as a lot of pork from here ends up in Japan.
I have had real Kobe beef and a couple of other types from Japan (yes, the details are quite blurred how it got here, same with the whale and sea turtle I have eaten) and the stuff we are currently eating is not the same at all. All of that being said, if you can get a Wa-gyu brisket for $6 a pound, go for it, that is cheaper than the good Oregon Choice stuff I can get out here.
Let's all just cook what we want and quite trying to tell other people who is the better cook because you use some certain cut of beef etc...I can fark up a CAB brisket just as easily as a Rancher's Reserve brisket.