When I started using syncthing some years ago it worked, but it was still a bit brittle. I ran over time into several situations where the sync would just stop or not start, be slow, some error happened somewhere and the GUI did not show them properly, there was no built in reacting to file modification, just a regular sync interval. It was good enough to be used, but certainly not done yet.
Yesterday I installed it again on my main PC (part of a migration from a different linux distro) and I was impressed: The notifications when adding new devices arrived with a very small delay, syncing just worked, file monitoring is now built in, the error message related to that (inotify limit) was helpful.
Syncthing came a long way and is great software, congrats for reaching 1.0!