I would go with the firewire pre-amp vs the USB one. You might run into probs w/ running 24/96 over the USB bus. One thing though, the firewire Edirol might not be able run stand-alone (without the laptop in the chain). That means that you might not be able to run it w/ your MD or JB3 or DAT, whereas the UA5 can be modded to run stand-alone.