Bit perfection is a concern for Digital to Digital dubs, such as DAT transfers
A/D and D/A isn't a bit to bit process
I hope that helps...
BTW, latency, sonic transparency,and jitter may be of bigger concern to you.
The MiniDAC is a nice box.
I like the Benchmark, others like the Grace M902, there are a few other great players in the game.
In short, you could do allot worse than a MiniDAC!
No one else is doing Firewire to my knowledge, and Firewire has the reputation of being far superior for constant stream data than USB2.0