I personally recommend DAT tape drives to all my clients. Travan is slower, less reliable, noisier and the tapes are a LOT more expensive that DAT tapes. DAT drives are more expensive, but you quickly make up the difference in the cost of tapes. Especially if you waste one or two. As I understand it, you cannot reformat Travan tapes if you accidentally erase them, but DAT uses unformatted tapes so if one is damaged by a stray monitor degaussing you can still use it. Also DAT does a read-after-write so for most backups you can skip the compare with relatively small risk compared to Travan where there is no read-after-write. My clients that insisted on the less expensive Travan drives have paid me the difference in cost for my time when they had trouble with the drives and/or tapes.

Also, DAT tapes are so cheap that some companies permanently save one DAT tape per week just to have a continuous archive. When comparing prices, look at the price of the drive plus a half-dozen tapes (I recommend AT LEAST 4 tapes in rotation). Then think about how nice it would be to have another half-dozen tapes for archival purposes.

In my experience ADR tape drives are good too (That's what I'm using right now, but I've also got an old, smaller DAT), but I can't recommend them right now because OnStream USA went bankrupt and was bought by a company in the Netherlands that also makes ADR. (ADR is a Phillips licensed product.) Their older SCSI 30 GB drive is also not 100% compatible with standard SCSI tape command standards, so it requires special drivers. OnStream and Veritas had a falling out over this issue, so Veritas does not support the older drive in BackupExec.

If you are backing up < 6GB of data, you might consider the older DDS2 (4GB native) DAT drives as they are quite economical now. I prefer Sony's drives myself.

If you use a CD-burner not only do you have to hang around to to change CD's, but they are soooo slowwwwww compared to SCSI (or even good IDE) tape! They also generate a lot of heat if you have to burn several in a row. I haven't tried DVD yet, but unless you want to be able to restore your system to the exact state it was in a few years ago, I don't see the advantage. I use CD's for archival storage of data files, if that is rquired, but I write normal data disks so I don't have to instal my old backup software to access the files.

R.e. Backup software: Ultrabac is good software. I used it for a while, but it is not very user-friendly and, like nearly all software, you either have to do full saves every time or use a LOT of tape doing differential backups or spend a LOT of time doing restores with incremental backups.

You might want to take a look at Retrospect. I've been using it for some time now and recommend it to my clients. It is pretty easy to use (except setting up the scheduler is a bit harder than it needs to be) and restores are really nice. It appends incremental backups to the tape, but you can restore your system to the exact file set at any backup point, including NOT restoring deleted files. In a workgroup it is especially good because it only saves one copy of a file that appears on multiple machines. After backing up my 6 GB desktop, my 2GB laptop backs up in less than an hour because they are both running a lot of the same software.

FWIW that is my experience speaking out of the context of my work style. YMMV

...Jim