I just upgraded to 10GbE service from Ziply Fiber in the Seattle area:

Speedtest.net - ~9.3Gbps symmetric

iperf to Denver: ~9.3Gbps symmetric (~8 threads)

iperf to Minneapolis: ~9.3Gbps symmetric

AWS S3 Download with small files: 1.3Gbps

Usenet download: 7-9.5Gbps

Mounting my ZFS pool to an AWS instance via SMBv3 in us-west-2: 3Gbps (not clear what the limit was here)

GitHub (400MB): 1 thread 400Mbps, 16 threads: 3.3Gbps

Fedora ISO from local mirror: 1 thread: 1.4Gbps, 16 threads: 4Gbps

Will try to test Steam and such.