I love JupyterHub, but we've hit some real headaches in having it scale. At Virginia Tech, we have an introductory course for non-computing majors where students are using Jupyter through JH. At around the 70-student mark, we have performance issues. Considering that the course is eventually meant to scale much farther (hundreds of students), we're not really sure how we can make further progress with our current resources. I hope this new version has some performance enhancements (though I don't see any in the changelog). Last I talked with anyone about this was in the NBGrader project[1], where other schools were hitting walls with scaling.

[1] https://github.com/jupyter/nbgrader/issues/530#issuecomment-...