Using a good optical cable (e.g. from Sys Concept or from Lifatec) I have found the Mojo sounds significantly better than either Coax or USB. Now, using a cheap, long, plastic fiber things were very different, but as soon as you switch to a decent quality cable then optical should beat out the USB quite handily. Mojo seems quite sensitive to noise via USB, even using very high-spec cables. I believe Rob has posted in this thread that his preferred interface for Mojo is optical.