Smart update is very fast, too! Highly recommended.

The smart update feature adds and deletes files from a previous backup to keep it in sync with your current data in a fraction of the time it takes to do a full backup. This, along with stuffing the backups in encrypted sparse dmgs using disk utility or hdiutil, makes all my backup dreams come true.

Simply the best at what it does. Paid for it and use it every day. Devs are nice as well.