FireWire Vs External USB
USB is the standard method used to connect a computer to any of several peripheral devices, including cameras, flash drives, keyboards, computer mice and printers. FireWire is the name for the Apple Computer version of the IEEE 1394 connection method usually used with audio/visual components.
Advantages of USB
USB has become the standard connector for the vast majority of computer peripherals, meaning those peripherals can be transferred from one computer to another with plug-and-play ease and no compatibility issues. USB video capture devices can convert your old VHS tapes to DVD.
Disadvantages of USB
USB tends to be slower than FireWire; it may run from 33 percent to 70 percent slower reading data, and from 16 percent to 48 percent slower writing data.
Advantages of FireWire
FireWire also offers plug-and-play ease of use, and its reading and writing speed outstrips USB's. Six-pin FireWire also allows peripheral devices to draw power from the computer they're connected to, so that no external power source is needed for them. Most digital video cameras are FireWire compatible.
Disadvantages of FireWire
FireWire does not work well with low bandwidth devices. FireWire ports are not standard on any non-Apple computers. While six-pin FireWire ports allow for great use of peripherals, these ports are not included on all computers.