Not really.....but the quality of the final product is better.
Firewire allows you to send the DV signal directly into the computer if it is
equipped with a firewire input and the appropriate software and hardware that
can handle it. Firewire boards are available as PCI boards for Macs and PCs
often in combination with USB.
If the camcorders converts the DV signal to analog (you use the special cable
from camcorder that provides stereo sound and video via RCA plugs) you can
still get fairly good video depending on your video processing software and
hardware on your computer.
Otmar