FYI - I gave up on Speed Download. It was actually performing the better (speed wise) than Yummy FTP, Transmit, and Cyberduck. I didn't test it against Flow. But, regardless it is one clunky app to use for FTP purposes. The way Speed Download acts and handles the download/upload process is so bad I gave up on it. It now resides in my application folder, unused, waiting until the next time I get AppZapperHappy.
On a side note.
Flow, the incredibly cool, mac like, fast as ever, FTP app is out of beta and coming this Friday.