Bootable USB may be messy to prepare, but on the user end it largely Just Works.
As with many hardware-vs-software things (e.g. RAID controllers), Firewire performance was originally much better but USB caught up as processors got faster.
A standard for USB video streaming eventually emerged (at least, I have that option in my kernel), but it's fair to say it was much less popular than 1394. Mostly camcorders (at least consumer ones) became digital themselves, storing data on a filesystem and presenting themselves as a mass storage device.
As with many hardware-vs-software things (e.g. RAID controllers), Firewire performance was originally much better but USB caught up as processors got faster.
A standard for USB video streaming eventually emerged (at least, I have that option in my kernel), but it's fair to say it was much less popular than 1394. Mostly camcorders (at least consumer ones) became digital themselves, storing data on a filesystem and presenting themselves as a mass storage device.