Actually there is an alternative one should really look at : drive snapshot from a German developer:
http://www.drivesnapshot.de/en/This small footprint program is really very powerful, does differential imaging, allows for excluding files & folders, has many interesting options. Combined with BartPE CD for bare metal restoration, it is quite powerful.
Can even image floppy disks and USB sticks.
For a more polished GUI, there is also O&O DiskImage 2.1. I must say I have made many successful system disk (XP) restoration with drive snapshot, never really with diskimage 2.1.
DiskImage 2.1 also does incremental imaging and allows to merge incrementals with the base image if required. Unfortunately incremental imaging is not faster than full imaging, it only saves space. Drive snapshot differential imaging is much quicker.
Drive snapshot has a powerful yet easy command line interface that makes it simple to schedule backup using XP task scheduler. It seems O&O DI2.1 lacks any scheduling function.
Just my 2 cents.