Although “it’s easier to say ‘USB doesn’t have the sustained throughput required for video'”; that doesn’t explain why. I had to clarify because two posts said that USB ‘wasn’t fast enough’, which is technically not true. That’s why people get confused by the different specifications and applications of USB and Firewire. As professionals we try to avoid wasted time and wasted money.
Plus, for crying out loud, it’s not really covered in the freakin’ manual. ;