Are you implying that using IPv6 lowers latency and increases throughput?
The throughput issue may be because the IPv6 network is less utilized and or uses more efficient routing, but the latency is less.
Here's Facebook's information on how IPv6 is faster: https://engineering.fb.com/networking-traffic/ipv6-it-s-time...
> We’ve observed that accessing Facebook can be 10-15 percent faster over IPv6.