I would argue there should be no audible difference. But I can only comment on Optical, Coax, and Denon-link, of which Denon-link is easily the best connector by my ears. But why would you bother with the Denon-link if you can use an i-link? The best sound comes from processing the bits in your receiver, and the only way to get the SACD (DSD) bits is with an i-link.
