If you want to be sure it works, try to copy it 100% full of stuff and test whether that stuff still works. (yes, it's a tedious job :-)
Heh... tedious and not very accurate. Might want to write a test program that makes a bunch of various sized files, and then tests to see if they can be read back accurately. Maybe 10 files each, starting with 10kb, and then 10 100kb, 10 1mb, 10 10mb, and the rest in 100mb files, just to kick it to the end of the drive. ;-)
Would be a pretty simple program in any language, and if you did a little research and tweaked the file sizes (mine are guesses), it could detect things like MaxTransfer problems, or glitches that may be introduced in SCSI data, as well.
Hmm... Maybe I do come up with a good idea every once in a while. ;-)