I feel Sonos have really missed a trick by not opening up their API more. Most of the features I had a reverse engineer or check from other libraries. Their own apps have also not exactly gotten better. For example, I _HATE_ the unified search feature, it makes the search slow and sluggish. Controlling the speakers from Spotify directly also never worked glitch-free for me. Other niggles have to do with the grouping features, which are also a tad flaky and sometimes time out or only partially group. Most of all I am annoyed by the frequent updates asked for, without the ability to "pin" the speakers to a version and download a specific version of the client app.
All that said, I love their speakers because they sound good. The old Play 3 and the Amp especially. I feel they should focus their efforts on making the apps snappier and faster, not much more feature rich.
[1] https://github.com/pascalopitz/unoffical-sonos-controller-fo...