I love SynchBack Free, for synching, too. However, it does not do incremental back-ups. For incremental and differential backups, You would need to purchase the the SE edition, which is $30 US.
Here is a comparison chart of the three diffent vesions. I have not tried either of the paid versions, but I have been using the free version with various versions of Windows and, recently, Vista x64. I now see the chart indicates Vista is not "fully" supported by SynchBack free, although it has been working for me. I am seriously considering trying SynchBack SE now, bc it appears there are more options for synching and it does officially support Vista. I use SynchBack for keeping my documents synched between my laptop and desktop machine and it often takes a while for me to sort through the various synching choices. So, the added synching options may prove useful for me.
I have recently switched to using True Image for incremental back ups. I bought it for making offline restore images of my boot partition, but the data backup capability has been a nice bonus. You can set it up to run on a schedule, or run it manually.. It can do both incremental and differential back-ups.. you can password protect and encrypt your backups with AES, too. I have also used NTI for incremental backups in the past, and it worked well, too. I think that one is $20 US, True Image is $40 at Newegg at the moment...