How many files are you able to handle, remotely, with Nuclide/Watchman?
Does it work if the remote files are on an NFS share (i.e. spotty inotify/fanotify support) mounted onto the server you're SSHing into (no, the NFS share cannot be mounted directly on the workstation)?
How many file-change events (on your workstation or on the remote) can this system successfully sync/handle in a short time? If there is, say, a 250k file alteration that happens due to checking out a branch, is there an indication that it detected the changes and is making progress syncing them, or does that necessitate a manual sync?
Context: I've worked in environments where local editing and manual sync got really annoying: for compliance/regulatory reasons, certain tools, e.g. source control, were only available on the remote server, so having all code on my laptop and manually syncing to the remote got quite tedious. Even better, the significant (i.e. I might conceivably need to open them/run tests that touch them) number of source files in the remote repo was in the tens of millions. I wasn't able to get any incremental sync/change-detection systems working successfully: on my workstation (OSX), large changes would overflow the fsnotify kqueue, no matter what wrapper around it I used. On the remote, watching was either unavailable (due to the age of the Linux server) or prone to failures in the event of large changes in files (e.g. checking out a new branch).
I've spent a lot of time mucking about with lsyncd, unison, and lots of other tools, and eventually gave up with the conclusion that directory-diffing is too slow given slow remote filesystems, and change notification systems aren't up to the task of managing bulk changes across a huge repo. Watchman sounds really promising here; I'd love to hear more about your experiences with it.