Might I ask those who have an M1 or M3, how you're feeding the DAC? I've just got a used M1se with the MDX update and Ethernet and I'm swimming in indecisiveness. My existing setup just plays Bitperfect/iTunes from my laptop w/ my 3TB library on a portable external HD, through Airplay to an Airport that connects to my existing DAC via mini Toslink... but I want to upgrade now that I'm switching my DAC to the M1.