best description I have ever read of syncthing. they should put this in their readme or about page. describes the pros & cons in an honest way. I've had all the problems you describe and will probably have them again in the future, be confounded, be frustrated.

I get (mostly) worry-free backups

except this; it's sync not back up. ;) but it is very backup-like and in some situations does the job as well or better than backups

I <3 syncthing nevertheless