So I'm not Atmos capable yet (its close though), and my stream gets downmixed to 5.1. I found the mix underwhelming. Several times I found myself checking to see that I didn't accidently swap a sound mode or have a malfunction because I couldn't tell the rears were playing. Sometimes there is just enough rear elements in place to let you know its all as it should be. Its not quite Plastic Ono Band non-discreetish, but its within shouting distance.
I don't think it has great sonics either. The midrange just seems so sucked out, maybe its bright? maybe its me?
I resorted to checking other previously streamed spatial tracks that I knew were discreet. They played fine. The Pre/Pro says its getting 7.1 48kHz each time.
But while browsing I noticed an Atmos mix of Rumors was available also. I went to that for a bit of comparison. I selected the Buckingham tracks and was amazed at how much better the mix and the fidelity was. I've had the Rumors DVDA since release. I haven't compared the stream to the 5.1 rip yet, but my guess is the stream does it justice. It will be interesting to compare the full on Atmos version.
On the plus side, I think some of the material is very listenable. I think it could be a grower. Not crazy about the drum machines. I'd be hard pressed to go higher than a 7 on this if it were a poll.