Client needs as simple as it gets.
5 zones of music required.

They do know how to use their Spotify app, and from what I am aware, Sonos can be set up to be controlled from the Spotify app.
I am familiar with Bluesound and when in Spotify, you just select the Bluesound Amp (zone) you want to play in. I assume with Sonos this is basically the same.

Only reason I cannot use Bluesound for this client is they also use Sirius Radio and it is not available within the Bluesound app.

I need to make this as simple as I can.
I cannot tell them to use Sirius app and remember to Bluetooth, and then use Bluesound app for their music etc.

Use spotify app or use Sonos app for your music (itunes library), Sirius or Tune In radio.

I do not think there is anything else out there that could make this any easier, is there?