Interesting... CarbonCopyCloner is "not recommended." I gave up using it a couple of years ago because of serious problems, but I still read posts where folks give it Two Thumbs Up.
A lot of people are reluctant to pay for utilities like the ones reviewed, so they try to make the free programs work. There have been a number of posts on TS about Retrospect and problems associated with it, and yet some people persist in trying to get it to work properly; I stopped using it years ago even though MacWorld always gave it glowing reviews. Apparently the reviewers never actually tried to use Retrospect...
Since backing-up is so critical, cutting corners when it comes to this kind of software is indeed Penny Wise, Pound Foolish.