if you’re thinking of buying a new One SL, you ought to keep in mind that it’ll only work with the newer Sonos S2 app.
This won’t be a problem for every Sonos owner, especially if you bought all your Sonos devices in the past year or two. It might be an issue, however, if you’re still operating a mix of newer and older Sonos hardware. Namely, the “legacy” Sonos products that were “killed off” last year. Those legacy gadgets will only work with the S1 app, and although Sonos committed to providing updates for these devices, controlling a mix of legacy and current Sonos gadgets isn’t possible on the S2 app.
You can’t roll back from the old update which basically only seems to add rounded corners to backgrounds and break in dark mode – except that you allow Sonos to spy on you through the built in microphone with S2.