Syncthing is under my "want to like" list but I gave up on it. I'm a one person show who just wants to sync a few dozen markdown files across a few laptops and a phone. Every time I'd run it I'd invariably end up with conflict files. It got to the point where I was spending more time merging diffs than writing. How it could do that with just one person running it I have no idea.
My Syncthing experience matches Oxodao's. Over years with >10k files / 100 gb, I've only ever had conflicts when I actually made conflicting simultaneous changes.
I use it on my phone (configured to only sync on WiFi), laptop (connected 99% of the time), and server (up 100% of the time).
The always-up server/laptop as a "master node" are probably key.
The conflicts come of course when you edit a file on 2 devices before Syncthing had a chance to sync them. I mostly solved this by running Snycthing on a server as well as on clients, so that at least the server is always online, as a point of synchronization. So now I only get conflict files, if somehow my phone doesn't have Internet and I edit files on my phone, which happens very rarely.
I had this when I had a windows system in the mix. Windows handles case differently in filenames than linux and macOS, and it caused conflicts.
Same. I don't know why so many people like syncthing.
That should not happen. I use it a lot and never had this issue, there maybe is something wrong about your setup.
A good idea is to have it on an always-on server and add your share as an encrypted one (like you set the password on all your apps but not on the server); this pretty much results in a dropbox-like experience since you have a central place to sync even when your other devices are not online