I'd heard so many bad things about problems with system restore that, like DavidR, I ditched it ages ago. While it's not a true disk imaging app, my system came pre-installed with Farstone's Restore-IT, which works pretty much the same way and automatically creates a new "restore point" (disk image, saved to a hidden partition on the main drive) at the first boot-up each calendar day.
There's been at least one occasion when I uninstalled something I didn't intend to, and restore is fast enough (<5 min. for roughly 10 gig used on my drive) that it was much faster to simply restore from that morning than to re-download and re-install. Like most imaging apps and their close cousins, it's unfortunately an all-or-nothing restore, so any updated files lose their changes. In practice, that uusually means nothing more than avast having to repeat one or more updates, which is no big deal.