Sonos Con:
It's effectively impossible to get it to play an XM stream indefinitely, as there is no way to send it a direct command to goto channel 36.
As was mentioned before, if you have multiple XM accounts for a corporate campus, the favorites are useless, as they are shared across the whole system.
You can set the 'alarm' to trigger every 4 hours, which will you allow recall a specific XM channel, but if there is any kind of network hiccup at the exact time of the alarm. the Sonos
will be unable to lock onto the stream and you'll get an audible chime coming out of all of your dist audio speakers.? Now someone onsite has to turn it off or it will keep going and going and goi.....
Autonomic Pro:
You have the ability to both monitor play status accurately and send the MMSProtocol commands that allow for direct reference of basically everything.
If the stream ever stops, you can just monitor the Stop Fb and trigger a terminate stream, reacquire stream sequence.