was just reading on FireWire 800 vs. USB and the transfer for USB is 280MHz vs 3200MHz for FireWire 800. That is one hell of a difference in speed. I have seen the difference on my mac but only when working with video or audio files. I will say this about USB, it is a hell of a lot more stable on MAC's than on most PC's
eSata > Firewire > USB for external connections =D