I have searched and cannot find a thread dedicated to options for FTP apps for Mac. I have found stuff about FTP problems, but nothing about where to start so I can use my Universities "Filer" program.
This is what I've always used and recommend it because never had any problems with it and its free.
Though I do have to agree the UI is a bit messy, especially on low res screens it get a bit cluttered but you get use to it. I'm not sure if you can change the UI because all I would use it would be to connect to my FTP, drag and drop files and thats it.
RBrowser and RBrowser Lite are both pretty good. Not sure if they're around and if they've been updated, we still use an old version here in the office.