I called Benchmark's technical support and spoke to them at length about your assertion that USB is superior to Toslink coming out of the Airport Express. They assured me repeatedly that Toslink would be "identical" to USB.
I know Benchmark says that it sounds identical. However, I can tell the difference between Airport Express (AE), Slimdevices transporter fed via toslink to the DAC1, or directly to USB. Direct via USB it better with a tighter sound, less glare in the highs, and more low lever resolution.
That allows me to save several hundred dollars by skipping the USB.
I would go with the USB version of the DAC1 in any case:
- More flexibility down the road as you can try USB direct.The excellent USB implementation in the DAC is one of the main reason to go with the DAC1USB in first place.
- Better driver stage in the USB version which is supposed to sound better than the last incarnation of the DAC1.
- You save yourself the $100 for the AE.
As for the interface, it's a matter of personal taste: Frontrow on a larger LCD screen, clicker software with a PDA, Laptop in you lap. Try them out if you can before settling on one.