For me it was sort of the other way around, I had paid for a SuperDuper license years ago, and I went and looked at both it and CCC and saw that SD would work for backing up my new machine (which has Catalina on it out of the box). I agree that ShirtPocket's aesthetic is old skool for sure, but I have no complaints about the actual scheduled backups (well, actually one, which may not be their fault, I have it scheduled to dupe my SSD once a week in the middle of the night, and I notice that my machine won't sleep after that is completed).