FWIW I've had excellent service with Paragon software - IMHO heads & shoulders above Acronis.
Programs like Rollback are perhaps a more complicated solution than disc mirroring when you need that level of redundancy (IMHO you usually don't). You have system and program software that doesn't change that often -- a few times a month depending on updates -- so it's inefficient to expend resources on archiving (or even monitoring) them more often.
I think it pays to use a bit of common sense... When you install random small apps, the cost in resources to archive them is often more than just re-installing if something happens before the next disc image. Some minor updates to Windows (&/or other software) fall into the same category.
I take the opposite approach to software like Rollback: I was taught to design for the usual -- that's where you want your greatest efficiency -- then have procedures in place to treat the exception... I have ample backups if needed, but I don’t force my systems, or myself to constantly work around creating backups. That’s NOT the primary purpose of either.
Data of course changes - some critical, some not. For the critical stuff there are all sorts of programs that maintain sync (of folders you select) with another storage device/location, and back things up manually, on a timer, or by watching for changes. This puts the focus where you need it.
If you want/need access to replace just damaged or missing files, like ShadowProtect advertises, & assuming you know just what's damaged or missing, a good image backup program will let you restore at the individual file level. Of course it’s still smart to ask: “Is it worth it”? If you can restore an image faster than you can determine what’s wrong, by restoring individual files you’re shooting yourself in the foot. I've also found nothing beats a simple zip archive for quick & easy access of individual files. However I’ve found backup programs storing compressed versions of your files much less efficient overall than the image type... they take much longer to compress &/or restore, & they usually don't perform as well with *hot* files (those in use). Boot restore discs are also more common with image backup programs.
Restoring files is a matter of copying them from one place to another, unless you’re using something like MS Shadow Copy in Vista, where theoretically you may just have to rename. Copying files isn’t necessarily going to be faster with one product versus another, so I take ShadowProtect’s ad copy with a large grain of salt.
According to the mini-review on DonationCoder, FirstDefense-ISR is very roughly the same thing as having several Windows installs - you choose your system via the boot loader when your PC (re) starts. The main cost is disc space [I don’t know if there are any performance hits], with a secondary loss in defrag times I’m imagine - the savings is however long it takes to restore a disc image (less than 20 minutes for a compressed 18 GB image using Paragon software on this PC - the only restore I’ve done in memory). I’ve restored a disc image once this year, & that because I intentionally butchered my Windows install trying to get an Adobe product installed & working. IMHO it’s a better choice to store a backup image on another drive (& remotely), use profiles in Windows as necessary, & if needed have a multi-boot PC. If your environment can’t wait 20 minutes or so to restore an image, have a copy of the system drive on the shelf... plan for the everyday, be prepared for the exception.
Putting backup archives on DVD is great for cheap, off-site storage, but you'll take a performance hit restoring, have to worry about poor quality media, & if there's a writing problem, often have to restart the entire backup -- I normally split my image archive files into chunks that can be burned to DVD for remote storage (I actually only burn maybe every 5th or 6th image), but leave the originals on the back-up drive. If I have to restore a drive & need to use the DVD copies I take a hit, but the odds of that happening are much less, & the backups I don't burn go much faster. Using a single drive for everything -- windows, software, & backups -- is risky, since hard drive failure is more likely to bite you than most anything else.
IMHO... & in a nutshell... while we all need to realize that problems happen, & plan accordingly, you can focus too strongly on what *might* go wrong, to the point that you’re robbing resources that should/could be spent on getting things right, improving on success.