When Type A Learning Agency migrated from CVS to Subversion, we tested all the Subversion clients and SmartSVN was the clear winner...
What's New in SmartSVN 7
SmartSVN 7 supports the Subversion 1.7 working copy format and comes with a couple of smaller improvements.
The new centralized metadata storage of Subversion 1.7 resolves several issues (like problems when renaming a directory without Subversion tools) and gives improved performance for various operations. For more details about this new format, refer to the Subversion 1.7 Release Notes.
xMerge has not yet been ported to SVN 1.7. As a work-around, you may continue to use SmartSVN 6.6's xMerge together with a Subversion 1.6 working copy for your merges.