DAC1 or DAC1 USB?


I have decided to try out the DAC1 in my system. Does anyone have any experience with both versions of the DAC1? I have been told by Benchmark that a few things were changed from DAC1 to DAC1 USB but I find it hard to justify a 30% increase in price especially when I do not plan on actully using the USB option at least for now. Any thoughts? Thanks in advance.

My very modest setup:

NAD (5 disc changer)
Stratos Amp
Harbeth 7ES II Speakers
Rotel 1055 (used as peamp, looking to use the DAC1 as a pre and dac)
kego
If you don't use the USB feature there is really no reason to buy the USB version - at all. The important features (e.g. output impedance) of both are up to date for both (I think) - best call Benchmark, must better than waiting for someone to relay potentially inaccurate info.
Benchmark updated xlr output stage with stronger driver LM4562 (and changed/lowered values of divider network) on DAC1 USB. Non USB DAC1 has probably still older NE5532 but calling Benchmark is the best option.
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Get the USB,buying the nonUSB version is like rewiring a house and not running extra wires for the future.....whats 300$ in this goofy business?YMMV,Bob