RT-AC66U B1 & RT-AC68U USB 3.0 speeds

Would anyone using a RT-AC66U B1 or RTAC68U with USB 3.0 and Tomato be willing to share their USB 3.0 read and write speeds over a LAN?

Thanks if you have one.

With a RT-N66U, USB 2.0, and Tomato can read at 17 Mbps and write at 13 Mbps over a gigabit LAN.