I used to run linuxserver’s syncthing image, but I found no real difference (besides there being one more potential point of security compromise), and switched to syncthing/syncthing.
What’s the difference? Is there even supposed to be a difference, is linuxserver’s a legacy from a time syncthing didn’t have its own Dockerfile + docs?
They do their own images for all kinds of stuff, you’d have to ask them. I would guess it’s so they have it available from a source they trust (themselves) and so that it uses the same pattern of init system as all their other images. I find that init system overkill and unnecessary. YMMV.