The Leap Motion Controller will work on both USB 2.0 and USB 3.0 but in the current software will only utilize USB 2.0 data speed.
We designed the controller to use the USB 3 micro B connection in case we ever wanted to activate USB 3.0. However, over time, we were able to achieve performance improvements on the software level without requiring higher bandwidth and decided to stay with USB 2.0 due to the system demands of VR headsets.