Check out Resilio.
I've used both for 10 years now, rarely have issues with either, and I sync (with Syncthing) hundreds of gigs between about 8 devices, with about 20 different sync jobs, every day.
You do have to configure ST exactly how you want it, and know what that means.
I've been able to move the config 3 times now as I've migrated systems - you stop the service, copy the config files (ensuring the new system has the same folder structure), then start it there. Not for the faint of heart.
I do think Resilio is a little more robust, but it's much harder on memory/battery for mobile - so much so I don't let it just run on my phone and only use it when I want to sync specific files over (using it's Selective Sync feature).