Better? That's debatable. When it comes to a particular forging, better is in the hand of the beholder. From my personal experience, Kyoei forgings are some of the softest. That leads to that "hitting a marshmallow" feel when you strike the ball, but that isn't for everyone. Some people like a more positive feel when they strike the ball. Also, Kyoei does many forgings. They sell clubs with their name on them, and I know they do Vega clubs. Outside of those, I'm not sure. But, Miura is not a Kyoei forged club, I don't believe. I think Miura does all their own forging. If you talk to anyone that's ever hit a Miura, they'll tell you that they're the best blades out there and worth every penny. I haven't had a chance to hit them, but I'd like to.
I have hit some Vega irons and they are very nice sticks, but I've also hit some Endo forged irons (Nike Forged Blades, my Ben Hogan Apex, and Bridgestone J33B) and they're all just as good, in my opinion. And much, much cheaper. You can get a set of any of those irons for $200-$300 in very good condition. The Vega and Kyoei clubs will be quite a bit steeper and will be harder to come by.