IMO it's not worth bothering with anything other than FMS. It's excellent.

The only practical difference between serial and parallel cables is which port on the PC they plug into. Parallel uses the printer port , serial the COM port. Note : these only work with Windows 95/98/ME. They will not work with Windows NT/2000 or XP.

For those newer operating systems you need the PIC version which is also a serial port cable but a more complex circuit using a small microcontroller. It is much more reliable and works with all operating systems but it is more expensive to buy/build.

Steve