I agree with most points above. But one thing I've found invaluable with Overleaf is its git bridge. This allows me to continue working on a paper from within

I agree with most points above. But one thing I've found invaluable with Overleaf is its git bridge. This allows me to continue working on a paper from within emacs, using git as I normally would, and then sync to the server where my co-authors are comfortable (using the web interface). I know of ShareLaTeX's support for github, but as I understand it the repository must be public (a non-starter while working on a paper that won't be public for months). I would be very happy to learn I am mistaken about the last point, though that may still mean that a paid github account is necessary to use a private repo. I would immediately pay for a premium ShareLaTeX account if there were an equivalent git bridge that I could use to sync with git repos on my own server.