Thanks for the replies everyone.
erik, I'm still not 100% sure what rune actually is. It kinda sounds like Plex? Basically a front-end interface for accessing music? My biggest issue with roon is that it doesn't support spotify, which means I'd be maintaining my own music database, or hunting around. I admittedly haven't tried Tidal yet, but I'm not sure it would have everything I want, my music taste is all over the place, and I feel like I would have to supplement.
archguy, I've tried chromecast in the past and they were nice and sounded fine, BUT, room linking and zones was awful. maybe something like roon as a front-end would solve this, but we have an open floor plan house (which I think is the main issue here) so having 2-3 zones linked gets a bit tricky, and was a real pain to setup. I've been trying to abandon sonos for some time now, and I actually sold everything, tried chromecast, and ended up going back to sonos again.
photomax, I really hope a bunch of people dump sonos based on the last announcement. for the past year or so, it's been completely unrelaible and garbage. I was ironically one if the early adopters (and even a large US dealer before they went 'mainstream'). In the early days, it was amazing and always worked. But now it's so bloated and unreliable, I find myself playing significantly LESS music with it, because it's always a pain and it doesn't always work. After 30 seconds, it will lose connection, skip, or stop responding, etc. I've been on the phone with them several times over the years and they can never seem to fix the issue. Sometimes it starts working again, but then a new update breaks it (and the updates are often and mandatory).