what is the missing link?

[blair.athol]

What computer are you using? I assume it's an Apple?
Knowing that WiFi does not work, I have it disables and just using Ethernet wired connection.  If your computer isn't near, no worries, get a pair of power line adaptors. There are plenty to choose from. (http://www.amazon.com/s/ref=nb_sb_noss_2...ne+adaptor)
Below is an example of my setup.

MacPro -iTunes  -Synology NAS (iTune library)  -Devialet AIR -D800 (ethernet)  -Cremona M
I am using Remote App from Apple to control iTune remotely.  I believe you have all these in your set up already (except perhaps the power line adaptor?).  So it's FREE! Simple, convenient, works like a gem. No issues whatsoever.
Don't sweat over WiFi, it's a known issue and I tried and I have decided to abandon that route.  I believe the beautiful casing just nullifies the WiFi antenna.
I am considering another simple option.  I am getting a Mac Mini (CAD$599) to store my music files and run as a server.

I have compared ALAC & FLAC music files in my system and I found no difference in sound.  I know many may disagree, but that's what I found in my system.

So here's what I do and it works just great, simple and inexpensive. I hope you'd find this helpful. Good luck.

+1 I can only agree!