CrossFTP is an excellent FTP client. CrossFTP Pro is a synchronization tool and FTP/FXP/FTPS/SFTP/WebDav(s) client.
About this version
CrossFTP 1.38 is a major enhancement release. It significantly improves the start-up speed, improves system integration for edit/open with operations, starts to support the Bonjour (ZeroConf) service discovery protocol, adds beta support for PRET, and fixes a number of bugs. CrossFTP Pro adds a powerful synchronization/backup tool for directories between local file system, archives, and remote FTP/FTPS/SFTP/WebDav(s) system. (via luKas’ shared items in Google Reader)