FYI, folks, got one and so far, it's been driving anything i threw at it just fine, incl. Focal Spirit Classics, Grado Labs SRs and some other less demanding stuff (mostly various in-ears and STAX SR-001).
You can find a somewhat informative teardown here:
http://www.qobuz.com/fr-fr/info/Hi-Fi/Bancs-d-essai/Denon-DA-300USB-Japanese174996
You can find a somewhat informative teardown here: http://www.qobuz.com/fr-fr/info/Hi-Fi/Bancs-d-essai/Denon-DA-300USB-Japanese174996