Well, I have to say that Harmonoid is the best one I've found, it has a ton of cool features, it works and it allows you to be able to see your collection by album and it doesn't use Electron. Right now its development has stalled a bit but it's still pretty much in good shape, though.
Looks gorgeous. Unfortunate that Subsonic is under "likely impossible" features, but I will try this on my home PC at least.
What do to you use right now to connect to a Subsonic server? I've used Strawberry and Sublime. Is there something else?
Oh, wait, there's also this mopidy backend that works fine but can't remember if it's Mopidy-Subsonic or Mopidy-Subidy.
I use Sonixd and Feishin. Feishin is the re-write of Sonixd, but only supports Navidrome currently (which is actually what I need; apparently *sonic support is incoming). Sonixd still works though, and is nice.
Never heard of them before, thank you, I'll be checking them out.