The difference between Firewire and USB:
FireWire vs. USB 2.0 - Architecture
FireWire, uses a "Peer-to-Peer" architecture in which the peripherals are intelligent and can negotiate bus conflicts to determine which device can best control a data transfer
Hi-Speed USB 2.0 uses a "Master-Slave" architecture in which the computer handles all arbitration functions and dictates data flow to, from and between the attached peripherals (adding additional system overhead and resulting in slower data flow control)
The Wavelength and Ayre DAC's overcome any short comings in USB.
FireWire vs. USB 2.0 - Architecture
FireWire, uses a "Peer-to-Peer" architecture in which the peripherals are intelligent and can negotiate bus conflicts to determine which device can best control a data transfer
Hi-Speed USB 2.0 uses a "Master-Slave" architecture in which the computer handles all arbitration functions and dictates data flow to, from and between the attached peripherals (adding additional system overhead and resulting in slower data flow control)
The Wavelength and Ayre DAC's overcome any short comings in USB.