NICMART  I downloaded TidyUp and scanned two drives with important files. It found about 11,000 duplicates very rapidly. But TidyUp is so unclear that I wasn't about delete anything. The interface needs a major rewrite to make it crystal clear.  
(Version 1.4.9)

NICMART  I had the same experience with rudeness. This little company has a big arrogance problem.  
(Version 1.9.2)

NICMART  The problem with "no disk space" seems to be widespread, and often having nothing to do with the availability of space. It's hard to understand why SD would be written so that "no disk space" becomes an all-purpose explanation for failure, as it did when, during my copy of 54,000 files SD choked on 1 corrupted file. If there is a bad file, as the company suggested (probably correctly) to me, then why doesn't SD describe a problem with the file rather than offering a bogus explanation?  
(Version 2.1.4)

NICMART  FYI. After my failure with SD I downloaded and used Carbon Copy Cloner. I encountered none of the problems I had with SuperDuper and it cloned much faster. I don't discount that others have good experiences with SD, but this is what happened to me.  
(Version 2.1.4)

NICMART  I should add to my prior comment that, instead of reporting that a file is bad, the SD! error message says that there is no more disk space available. The utility should be more savvy than that.  
(Version 2.1.4)

NICMART  My first experience with SuperDuper! was with 2.1.4, and I'm afraid it didn't match the many positive reviews. I wanted to "erase and copy" about 550 GB from a two-drive 1 TB 0 RAID to a 1 TB single drive. This copy method is quite slow, taking more than 10 hours, so I let it work overnight. During the transfer of the 54,000 files, SuperDuper found one it didn't like after copying about 40,000 and I woke up to an error message. Rather than stopping the entire operation, SD! should be able to skip problem files and allow the user to decide later what to do with them. After some contacts with tech support, I resolved to delete the problem file and continue to copy. It finished fine. BUT! When the copying finished my 1 TB target drive reported a capacity of just 429 GB, and I had only 22 GB free. Half of my new drive's capacity has become invisible. Tech support has no explanation, but it would appear that SD! may have a problem copying from a striped RAID. But why, since, according to the publisher, it merely copies files? I've never had a problem copying from the same RAID before using other copy utilities (e.g., Deja Vu), even to a target RAID. Tech support was quick and cordial, but without solutions.  
(Version 2.1.4)

NICMART  I have tried to use Das Boot to install DiskWarrier 4 on a USB flash drive connected to a Mac mini core duo, but DiskWarrier doesn't show as a selectable option. The publisher didn't respond to my support request.  
(Version 1.0.2)