Yes - not subtle to my ear.
Probably not - USB sounded better to me than toslink directly out of my Mac Mini
Yes - Evo is way better than the toslink S/PDIF from my Mac.
I wonder how much source jitter makes a difference with the Rega Dac on the spdif inputs. We already heard that spdif inputs sound better than the USB input, but how much of that depends on the source of the spdif?
-Will USB on the Rega Dac sound worse than being fed spdif through the hiface EVO? Sounds like yes.
-Will USB on the Rega Dac sound worse than being fed spdif through a cheap onboard sound card?
-Will the sound of the Rega Dac be improved by the hiface EVO compared to using a cheap onboard spdif output?
If questions 2 is also yes and question 3 is no, then I know I can easily live with the Rega Dac as it can handle any digital source and manage the jitter so I don't have to have premium digital transports to get the great sound out of the unit. Being able to get the same great sound whether being fed by a Saturn, a hiface EVO, or the crappiest spdif computer output I will ever encounter...that would make the lack of async-usb acceptable for me. However...what is the answer for question 2 and 3?