I have two sonos systems in different locations and can’t say I’ve seen the play back / streaming issue.
Each system has a nas with my ripped itunes library on it that indexes daily at 2am.
Apart from sonos firmware updates I find it very stable and perhaps need a reboot of the sonos devices once or twice a year.
Access to spotify as a premium subscriber also just works.
The interface is reasonably slick and easy to navigate all in all despite the cost the ease of use make it worthwhile.
Though with Amazon Alexa, Google Home and Apple looking to get in on the market there could be some changes ahead.