Microsoft built-in backup provides only basic backup/restore operations.
R-Drive Image can also copy/clone disks, connect images as logical drives. When restoring, R-Drive Image can resize the disks and even convert them from one FS to another.
As to backup/restore of a system disk, R-Drive Image creates only one startup disk with the image on it, whereas you have to have a rescue disk for MS backup in addition to the backup one..
Add a more versatile task scheduler, scripting, and support for non-windows disks. As a topping, a better graphic interface. You may read more about R-Drive Image features in it help: R-Drive Image Features