First an answer to those with the audio not returning issue. There is a script you can add that is listed on the Chromebox wiki to fix the issue. The Wiki can be found here:
http://kodi.wiki/view/Chromebox go down towards the bottom of the page and there are instructions to fix it. This is for OpenElec only. It should also work on this box is you are using the generic OpenElec build for Intel hardware.
Also in OpenElec you can change the power off to suspend. It's not a total off but works well. I did have a problem with having an SD card in the card reader. The system would do exactly as some of you stated where it would pop back on a couple of seconds after it went to sleep. For me this would not be an issue with the Zotac box as I can IP control it utilizing the WOL that is not supported in my Chromebox.
Now a question for those of you running Kodi on Windows have you been able to playback either .mkv 3D or full blu-ray disc 3d? Or even in OpenElec for that matter?
I'm excited at the fact of using one box for Kodi with Netflix, Amazon and Hulu!
My Chromebox OpenElec setups run flawlessly but are unable to do 3D or 4K and I still have to use a Roku for Netflix, etc.
Mind you I'm a custom installer so everything is single button access without any noticeable delay in switching between Kodi and the other services. (and I'm sorry but your hamony won't do it as it takes IP control on the Roku, Kodi box, and receiver.) It would just be nice to be able to have one box do it all efficiently.