I am impressed by this software for 2 reasons:
1. it has a very simple, clean and easy to use interface
2. it does exactly what it's supposed to do
I went through a number of applications and spent over 12 hours trying and testing different things. What I needed is a tool to synchronize (and backup) my multiple USB drives into a single big USB drive and keep them in sync, as I add more stuff into it.
Since the USB drives are older I can't format them using HSF/HSF+ to get them working with Super Duper. So I had to find an alternative.
My single most important criteria was simplicity of use and I wanted the tool to have an interface where it lists pairs of folders (or drives) to be backed up.
I went through following apps:
Get Backup Pro, Super Flexible Synchronizer, Backup List, Super Duper, Carbon Copy Cloner, Synkron, Goodsync, Folders Synchronizer, SynkTwoFolders, Synk Pro, Synchronize Pro, Chronosync, iBackup, JaBack , Simple Backup, Deja Vu .... and several others.
From this list 3 were top candidates. Deja Vu (failed because of miserable interface), Synkron (failed because when it was supposed to do things it froze) and File Syncrhonization (no issues but one, see below).
This software is not replacement for Super Duper or CCC. It doesn't something different and it does it well.
My only complain about this software is that it has no scheduler. Yes, you can use the iCal calendar application to create an event. That's not the point because I can create an event for any application using iCal and/or Automator. I don't like to put computer related things into my calendar, but one way around is to create a new separate calendar for this purpose.
(therefore 4 starts for features list)
Overall, I am a happy camper with this app and I can recommend.