Every keyboard is powered by some sort of micro-controller. These micro-controllers are often attached to the USB port on your keyboard, so if you happen to break your USB port someday, or simply want to upgrade it from one port to another, a hotswapped controller can make that a simple task that you can do on your own. Just like hotswapped keyswitches, hotswapped controllers allow you to simply pull out your old controller and re-socket a new one without having to solder anything. Hotswapped sockets add a couple millimeters to the height of your keyboard, but it's the smart long-term play in terms of the longevity of your keyboard. Better safe than sorry!