Well, finally. ATV4 using Airport Utility for iOS finally streams at nearly 600MB/s. NO MORE STUTTERING streaming content from my iTunes Home Sharing Server. The old ATV3 with its pathetic 65MB/s is not missed at all. One thing a little strange is that when I set Surround to "Auto" the receiver sets itself to "PCM Multichannel" rather than DD. I do have a 7.1 receiver and set up. Perhaps changing ATV4 to Dolby Surround will fix it. I don't think PCM Multichannel is really outputting it to all 7.1 speakers like DD or DDEX when ATV4 is set to Auto. Anyone know?