It works beautifully. Realtime sync and conflict resolution between all the devices it’s on (My phone, laptop, and desktop).
I only have mine setup to work on the same network, but you could get it to work over the internet, but that’s much more security & proxy work.
If you wanted to do it all in the cloud. An (over provisioned) VPS, domain, and other configuration would still cost you less than what Obsidian wants for their live sync.