Genuine question: Has anyone ever had a multi-room Sonos set-up that has actually worked?

Yes for sure. Prior to the new app and firmware my system worked great.
 

Some people have a working system with the new app as well. 

Hmmm...🤔 My Sonos with 31 units works perfectly. Has so since 2015. If you are so inclined please provide information about your network. Are there any Sonos Bridges or Boosts in play?

I’m another - an 8-room system which was working better than it ever had before, just before the May 2024 app release.

My app was auto-updated in May (my mistake, should have had that turned off) and as soon as I saw my first “Something went wrong” error message I knew it was a very bad sign, and that it was time to revert to the old app. I’ve stuck with that, and had no issues since.

The main downside is that I can never upgrade the system of buy any more Sonos products (because that would mean different firmware, which would result in a forced system-wide firmware update, which would then result in a forced app update. But I can live with that.

I now have more Sonos Rooms than I have rooms in my house. All are working quite well aside from a few lingering missing features from the App update.

Apart from the Plex integration telling me “something went wrong” most of the time, my problems with the app are mostly cosmetic (loss of pictures with last used radio stations etc.). Grouping, the multi room part of Sonos, has always worked well.

I just don’t know if I believe ‘everything works well’ stories. I have always had my system disappearing, reappearing, individual components requiring factory resets, patchy music. Sonos, in my view, has to be the worst music speaker system in the market place today. I just home they don't suck in any more people to experience their truly awful infrastructure. 99,9% of people are better of with Apple Home Pods or something similar.

Unfortunately I doubt you’ll ever know the real facts (in terms of actual numbers of people with no problems/a few problems/a lot of problems). A forum like this doesn’t really give you any way to know that.

Dissatisfied people tend to only post a few times. People who post a lot tend to have invested a lot of time in their systems, and generally (but not always) tend to have got a workable result. I’ve spent many many hours on mine - which is why I’ve done my best to disable any future updates. Hopefully this means that Sonos can’t screw it up for me now that it’s working more or less OK...

The company has been around for 20 years now. Seems silly to think it never works well if it’s been in business for that long.

As for Apple Home Pods, I’m not up to speed with it’s customer feedback, but my undestanding is that it is not without it’s issues,  The fact that they discontinued the product for a while doesn’t bode well.  The system also doesn’t match the feature set that Sonos has, particularly if you are an android user.