The best wagyu I have had was in Tokyo at a small kappo-style restaurant done ishiyaki-style. Basically, smooth river stones are heated and the slices of beef are lightly seasoned and cooked on the hot stones. By the time the dish reaches you, the meat is sizzling and has cooked to perfectly medium rare.

There was not a lot of beef but jut enough for the fatty-ness to bring a burst of flavor without the sickness that ensues after such a fatty binge. I find large quantities of O-Toro to be the same as large quantities of wagyu.