As far as I have seen, SVN Manager is only a manager / admin tool and is not a web interface to SVN with diff and full tree browsing - trunk / branches / tags / revisions / diffs / etc.
At the minimum, websvn would be a great help to developers with VPS. Developers can store all the code securely on their own servers and not rely on some 3rd party source code repository which *may* be beyond budget in cases where one wishes to merely experiment with technologies.
Cloudforge is the only one with significant storage and a free plan, all others are just about 100MB or so. See http://www.svnhostingcomparison.com/
Also, Git users have https://bitbucket.org for private repos, true, but there is also some value in having one's own setup that one can backup entirely with a custom rsync-based script, IMO.