Wtf, their pricing model is almost as bad as the planned obsolescence. $15 a month just to connect your hardware? Ridiculous.
As a fringe benefit, it lets me use all of my old Sonos devices (as well as a modern Denon). And lets me listen to my FLAC music in a reasonably decent phone app as well.
In other words, I think the value proposition is sound. Importantly, their goals are aligned with mine: I want to listen to music and I pay them to maintain software that lets me listen to music. They want to get paid, so they maintain software that lets me listen to music. This is a very different relationship than most.
Works for me!