I just bought the 840C a few days ago...it is at about 75 hours of running time thus far. My 'reference' CDP is the Jolida 100 with a level II modification. In my A-B comparisions so far, I'd say the 840C has a titch more detail, though the more analog smoothness of the Jolida impresses me as easier to listen to over an extended period of time. I've been using the Audience AU-24 ICs for comparing, though my IC of choice is the Acoustic Zen Ref Mattrix II. Plenty of options to tweak going forward. I have had an Apollo in for trial one weekend...and I couldn't tell the difference between that and the Jolida, though I prefer the Jolida because of front loading, (perceived) build quality and a damn good headphone jack built in. Hope this helps.