Over the years, I've spent a lot on Sonos and let's leave it at that. I was a die-hard fan buying it for relatives and encouraging friends too. However, they made quite a few of my items legacy, 4 x Play 5s and a Connect that I used for proper hifi via optical out into Marantz DAC, Amp, Floorstanders, massive Monolith Plus sub. The cables on that system cost more than a Play 5.
To be fair, I always thought that it sounded great via Spotify and the Sonos Connect, but I swapped to Tidal Hi-Res Studio files via the Bluesound Node, and the difference is massive. No more background noise at 5+ vol, the soundstage is much more comprehensive, bass control on another level, and vocals/instruments are just popping. The difference is enormous considering the amount spent.
I'm gradually swapping Sonos for real HiFi because they will legacy more products, for example, after a few years when the S3 app comes out. I understand the business model, but it's not for me.
The Tidal audio files also sound much better in my car, but strangely, there is very little difference between Sonos products.