The hypers were originally designed for low thermal expansion, allowing tighter clearances, therefore fewer emissions during cold starts. They are inexpensive to manufacture, thus perfect for high volume assembly lines. I've never used hypers, because I've had cast pistons fail … and hypereutectic pistons are cast pistons. You can heat treat them until you're blue in the face, they're still a cast piston. Yes they're quieter during cold starts. I see no advantage to that, I've never purchased a piston because of how quiet it is???.
I've always use forged pistons, because forged pistons are truly tough. I prefer the toughness. Especially for an engine that might be revved high every once in a while. The Ross pistons have full round skirts, they're heat treated, and are drilled for wrist pin oiling out of the box. They are machined for thinner (more modern) piston rings. They can be custom ordered with an anti-friction coating on the skirts too. That's all the stuff I look for.