Yesterday I tried using the iLink(Firewire) cable link between the P5D5 and it sounds pretty analog, smooth to me. This isn't some "audiophile" approved item, just a cheap computer cable from the electronics store. Quite surprised/impressed by the sound I'm getting from it. With the remote on the D5 turned on, I can also switch between digital cables on the fly. Quite cool.
I'll let it run a bit more before reporting on how it compares with the dual XLRs.