Fetch, the venerable ftp client, has recently been updated and now supports sftp. I’ve used Fetch off and on for at least 10 years. It may not have all the bells and whistles of newer products like transmit, and it costs money as compared to the free fugu or cyberduck, but it’s rock solid and a comfortably familiar interface if you’ve used it as long as I have. $25, osx only.