I have this USB 3.0 WIreless AC1900 device:
It seems to randomly on booting come up connected to USB 2.0 or 3.0. Of course, the Internet Speed will be different, USB 2.0, around 250Mbps down (probably limited by the USB 2.0 transfer speed), USB 3.0, a little over 400Mbps which is my ISP...