Depending on what software you are using, you can have a five-tape set that is good for nothing but a paperweight if you have a single corrupted byte in the wrong place on the tape.

Not with DLT. There are several things done on DLT to ensure that errors like this are recoverable. It's all done in hardware automaticially, so even if "tar /dev/tape" is being used, data can be recovered.

DLT also has a minimum shelf life of around 30 years if I remember right.

It's also damn quick. Seek times aren't bad at all, and recovering a single file is no problem.

Of course you pay for all these nice things in DLT though.