I grabbed the download stats from the public Github API to put the usage reports into perspective (and give @calmh something to )
total downloads of all release files
732.080
total downloads by OS
linux: 462.135
windows: 218.493
macosx: 34.622
freebsd: 9.676
darwin: 6.184
solaris: 653
openbsd: 317
of course this does not mean unique devices because Syncthing downloads the update from Github, so here are the stats for the latest releases
0.10.21
freebsd: 789
linux: 71.446
macosx: 4.065
openbsd: 45
windows: 13.633
0.10.22
freebsd: 395
linux: 30.778
macosx: 1.796
openbsd: 16
windows: 6.299
0.10.23
freebsd: 514
linux: 48.962
macosx: 2.284
openbsd: 27
solaris: 2
windows: 8.343
The flux in the compensators™ is because some people have disabled automatic updates and/or only update once in a while skipping a release or two
Note: this post will be updated at random times depending on and available power sources