What would be the best solution considering, scalability/load and security, svnserve + xinetd or standalone svnserver? Thank you!
Don't forget there is always svn over ssh, and
mod_dav_svn, both widely deployed, and highly reliable.
One thing that I can think of as a benefit of doing it with xinetd is with regards to multiple repositories.
If you are looking to have one svnserve serving up multiple repositories, you'd need to use the -r switch, and load up svnserve.
However adding a new repository tree would require a restart of the entire svnserve process, possibly interrupting current users.
If you use xinetd it will automatically be picked up the next time the system is quite (and you don't have to wait around for it to happen).
At the moment that's the only advantage I can see to using xinetd.