I have nothing but bad things to say about DAT as a backup medium. For us, they never worked reliably and were always a pain in the ass.

IMHO, DVD-RAM is not yet proven as a reliable and easy backup medium. If you want reliable and easy, you want DLT. Period.

When we switched from DAT to DLT, suddenly life became easy. The drives and tapes are indestructible and rock-solid reliable. Everything just works, I never get tape errors. With DAT, I had to have the thing re-scan the tapes to verify everything was correctly backed up. Which of course meant that much more wear and tear on the tapes and the drives. With DLT, I've gotten to the point where it trust it well enough that I don't even need to do a re-scan.

Seriously consider DLT instead of DVD.