Using Personal Hotspot with Wi-Fi vs. Blue Tooth vs. USB?

http://www.iphonehacks.com/2014/08/usb-wi-fi-bluetooth-best-way-tether-iphone-ip ad-data-connection-personal-hotspot.html

USB: Fastest, single connection

Wi-Fi: Slower, but fast enough for most purposes; uses battery pretty quickly; multiple connections supported

Bluetooth: slowest, but uses less energy; single connection