Hmm, have you seen the price of my cables?? We have really suffered at the hands of the gold price, and our prices for our top end cables, which have a lot of gold in them has rocketed up alarmingly.
Since the computer is the master clock then the cable isn't transferring data in block mode, as it does in most other applications, and so the delicate clock timing has to be transmitted by the Firewire cable. So it suffers exactly the same issues as good versus bad SPDIF cables, for example. So the 'quality' of the cable matters, but more or less so depending on what it is feeding.
The benefits of Firewire and USB over SPDIF or AES/EBU are that the signal does not have to be locked onto so tightly, and Firewire is usually going to get a lower jitter signal out of the computer than USB.
Since the computer is the master clock then the cable isn't transferring data in block mode, as it does in most other applications, and so the delicate clock timing has to be transmitted by the Firewire cable. So it suffers exactly the same issues as good versus bad SPDIF cables, for example. So the 'quality' of the cable matters, but more or less so depending on what it is feeding.
The benefits of Firewire and USB over SPDIF or AES/EBU are that the signal does not have to be locked onto so tightly, and Firewire is usually going to get a lower jitter signal out of the computer than USB.