My ATV4 arrived last night, so felt the urge to go and set it up. Seems the ATV4 software is still very buggy which surprises me as I would have felt that really tvOS is still at its very core using iOS and a version of the ATV3 code in the background. What I have noticed with my 5.1 setup is that surround sound support is poor. If the surround settings are set to "auto", my amplifier reports that the sound is in multichannel mode. Dolby digital content plays in this mode rather than Dolby Digital, and whilst the sound does sound multichannel, I can't imagine that iTunes nor Netflix would want to pipe 5.1 using 5.1 streams of AAC which as some of you know would be a very inefficient use of bandwidth. If I set the ATV4 to "Dolby Surround" rather than "Auto", my Amp will correctly report "Dolby Digital". What is interesting however is that content I know is encoded with Dolby Digital + (e.g. some Netflix content), will only show as Dolby Digital, yet my Fire TV (yes, I do have both) will correctly play the content with the higher encode audio. Anyone else out there noticing these oddities? For what it is worth, the AT4 seems very much like a beta product at the moment rather than just an evolution as I was expecting.