Any good multi-threaded SFTP clients for Mac?

I am amazed that there doesn't seem to be a decent multiple connection capable FTP/SFTP client for Mac. The only one I've seen is [CaptainFTP](http://captainftp.xdsnet.de) , which looks awful, like it's from the last century. There's also iGetter , which is equally ancient, and not really set up as a browser, more of a download accelerator. I've been using lftp , which is **amazing**, but CLI only, which makes it a pain. Does anyone know of either (a) a "modern" client app which supports multiple connections, or (b) a GUI for lftp?