This section is from the "Version Control with Subversion" book, by Ben Collins-Sussman, Brian W. Fitzpatrick and C. Michael Pilato. Also available from Amazon: Version Control with Subversion.
Network protocol is stateful and noticeably faster than WebDAV.
You can take advantage of existing ssh accounts and user infrastructure.
All network traffic is encrypted.
Only one choice of authentication method.
No logging of any kind, not even errors.
Requires users to be in same system group, or use a shared ssh key.
If used improperly, can lead to file permissions problems.