The complexities of HTTPD/mod_auth_svn integration and its complex integration alterations between releases of Subverison are only some of the reasons I gave up on HTTP based access to Subversion years ago, and switched to svn+ssh. There are uses for web access to Subversion, but most of them are better served by the cleaner interface of viewvc for pure read-only access.
The other blocking factor, for me, was the default behavior of the Subversion client of storing the HTTP or HTTPS access passwords in cleartext. It's gotten better orver time, notifying users better of the risks, but the default behavior is still an issue.
