Both will work fine as long as you have internet but the keypad is MUCh better because you don’t need anything installed on your computer and you don’t need to physically plug anything in, so you can use it with an iPad even. I successfully paid my credit card bill in a Rome hotel with only my iPad mini. No way I could have done it with the USB dongle. The keypad also works with Macs but I doubt the USB dongle will.
