Since the USB3 memory sticks are really fast I expect they would maximize the speed of the USB2 port (480Mbit/s). I tried two sticks. With Disk Utility I got a sustained read speed of 40Mbyte/s but when I tried the write I only got around 10Mbyte/s. During write the speed frequently went down to very low after starting at 35Mbyte/s. I tried several of the latest distros and the result were the same.
The plan was to try to set a hard limit on the speed to and from the USB3 device. I didnt find any such commands. Could I tunnel the USB traffic trough a simulated network device I then can traffic shape?