I have used SyncBack for many years, and although that works very well, I never use the network backup capabilities and other features. I only need differential backup on a USB. It also proves to complicated for most of my 'not so IT-savvy' colleagues at times.
This one is easier. I just use the 'simple copy' option and it just adds/deletes/changes the files that changed in my source folder. The other options are a bit odd in how they backup with new backup folders created (which turned out to be empty even though I added a file in the source folder). Don't need them anyway.
What I like with this one is that it finds my Mozilla Thunderbird profile as well. Also you can select a multiple of folders as part of a single profile. SyncBack requires a separate profile for each folder (unless of course they are sub-folders of the main folder you selected).
So, if you stick to the 'simple copy' this is a very easy program to use.
License: Free Trial ($19.95) Details...