This does exactly what I want it to, easily and quickly. I use it for backup and bootable backup ("cloning"). I looked around at the free software, and the commercial. This came up tops at under $30 ($27 with the download discount) for my two systems.
Differences between "Backup" (from whole volume to root level on destination), and "Clone" (creating a bootable backup) are relatively obvious as are the particular settings (more or less intuitive).
Does a nice job of incremental backups (a little slower as it seems to err on the side of recopying a few more files than, say, Silverkeeper does, but that is just how it seems).
The interface is nice and progress well reported.
I use it with an identical (and interchangeable for added offsite security) pair of LaCie Porsche Design mobile 1TB USB3/2 drives, with 4 partitions. It treats each partition as a volume.
Once set up (I had to do a second run a couple of times to get a complete and clean destination set), it all works perfectly.