If I have people come over for dinner, invariably, someone will ask me to cook up some "A5 BMS 12" Wagyu from Japan. I'm not the one to judge a request like this. Everyone wants to try the extreme version – and it's helpful to calibrate Japanese Wagyu versus other kinds of beef by starting with extremes.
Why is A4 so great?
A4 Wagyu has slightly less fat and is not as overwhelmingly rich as A5 Wagyu. It still has the unique melts-in-your-mouth and the umami qualities which are unique to the Kuroge Washu breed, but carries a more beefy flavor profile and you can eat more of it in one sitting. Simply put, for most people, it's simply more enjoyable. Don't get me wrong, A5 is incredible. I like to say that A5 Wagyu is more of an experience than a meal. Whereas A4 Wagyu is both a meal and an experience.