As far as I’m aware, there’s no difference between the two. Entirely up to you, and which one you like “better”. 

Sonos radio does contain a lot, maybe all, the stations you can get through tune in.  However, they also have quite a few original stations that you cannot access through tune in.  IMO, that’s the reason to give Sonos radio a try.

Oh, sure, but that’s not the question asked, I thought. 

Personally I would suggest trying both radio services and see which service seems best and suits your own needs.

Here are two support page links that provide some information about each of those services within the Sonos system:

• Sonos Radio
• TuneIn Radio

I am looking for an advantage of using SONOS to play a particular station instead of TuneIn.

Is the SONOS station less likely to drop out, have a higher quality stream, more likely to connect, have a faster response time, etc?

@Sarno,

I don’t personally know the answer as to the sound quality of the general radio streams as I think the stations vary by what is being listen to and there’s no indication in the app to determine the quality. Connection times can vary, but I’ve not sat and compared that as I’ve not noticed any significant delays from either service. 

The Sonos Radio curated stations seem good quality even in the free version of SR, but are apparently HD (CD) quality if you opt to subscribe. Obviously the Sonos own curated stations are not on TuneIn. I think around the World TuneIn has 100,000+ stations and Sonos provides around 60,000, I believe. Sonos Radio HD is not provided in every Country that the free version is available. 

I personally tend to use both services via the Sonos App - I think it’s easier to just try them both and simply see which you prefer to use for the stations you like to listen to. Then draw your own conclusions from what you experience.

I couldn’t tell for sure one way or the other.  OPs first statement, if taken literally, is only partially true.  Sounds like we need a veen diagram.

Drop outs are a function of the streaming quality, your internet speed (rarely), how many/which speakers involved, and local network conditions.  The only factor that could be different between Sonos radio and tune in is the streaming quality. Obviously, lower quality streams require less bandwidth and thus are less likely to have drop outs than higher quality streams.  I don’t know for sure, but I doubt there is a streaming quality difference between a station via Sonos or Tune In.  If your having drop outs, I’d suspect the issue is better resolved looking elsewhere.

As an example there are some times where I’ve listened to a Sonos HD station on 4 group rooms and had some trouble with dropouts.  If I remove one of the rooms from the group, dropouts are gone.  If I reboot the router, switch wireless channel, network conditions may be addressed and drop outs gone.  If I switch source from Sonos HD to Sirius XM (SD), drop outs are gone.  Switching from Sonos HD to a Amazon Music HD doesn't change anything.

When you select a station, the SONOS players fetch the station URL directly. Likely Sonos Radio and TuneIn will deliver the same URL to the players. If one service offers an HD version of the station, but the other service does not offer the HD version, then the two versions are using a different URL. One URL might encounter issues out on the Internet.

A difficult to track issue might be due to the station using multiple servers at the same URL. One server could be causing issues that the station is not yet aware of. In this case trouble free play is not assured because you may be randomly assigned to the troubled server. In this case stopping, then restarting the stream might result in selecting a better server.