Comment on svnX

svnX is reliable, and nice as far as traditonal clients go, but I agree that there are better ways to do it.
SCPlugin is the TortoiseSVN "equivalent" for Mac OS X. http://osx.iusethis.com/app/scplugin
It's definitely getting there in terms of reliability. If it's serious mission-critical stuff you should probably stick to the command line client in any case.