It has support for both FTP and SFTP, automatic failure recovery, folder synchronization and more. What I really like are the "bookmarks." Basically, they're droplets that you can point to any directory in your online space. From there, you just drop a file you want transferred onto the bookmark and off it goes. Yummy FTP is good about asking if you want to make a new bookmark for new directories, as well as where you'd like them stored.* Other features include:
- Easy scheduling setup
- Can be scripted with Applescript
- Remote editing with your favorite editor
*Yes, I know that the current version of Transmit lets you create droplets as well, but I liked Yummy FTP's method.