I've been using Sonos for about five years - we've got a mixture of their products around the house, but not a Playbar. I love using the product (for Spotify, line-in (TV), and Radio streaming)
If I am totally honest, I would advise people to hold off on buying Sonos products right now. As a business they are have significant challenges. They recruited a new CEO in January and the founder left the business. Software development has been practically nill in the last 12 months, and they are laying off staff.
They did a great job of anticipating and riding the music streaming wave, but they're lagging behind in mobility and "smart homes". They have failed to see where the market was heading and now have to play catch up. They don't have any portable/mobile products, and they don't have any smart home integration - they keep promising Alexa integration but it's still not available. Should have been there at launch in my opinion.
I believe they are vulnerable to the "big boys" in the industry. They haven't integrated with other eco-systems which may be their downfall. Google, Amazon, and Apple are all working in this space now. Amazon and Google have both released home speakers, and while they're not yet a direct competitor to Sonos, they are heading in that direction.
Apple are about to release their HomePod product, and they are going to be the first to take direct aim at Sonos with this product. The problem that Sonos have is that to survive they need to integrate, but why will Amazon/Google/Apple want them to integrate? Those companies will probably continue to develop their own speaker technology and lock Sonos out in order to try and corner the market.
I am a happy Sonos customer, but I am worried about their future - they should have been more willing to integrate with third parties a few years ago. Now they have their new CEO it seems that they are willing, but I fear that the market may have left them behind.
Time will tell, I suppose, but I'm holding off with any further purchases for now and may sell in a year or two depending on how things unfold.
Interesting thoughts.
I too am a big Sonos fan - been using their system now for over 10 years and love it but as you say, it is a system that works in isolation rather than being truly integrated.
I've just ordered two new connect:amp for our extension so here's hoping it doesn't go belly up! (Mind you I did get a 20%+ discount!!)