I've used this unit a bit for a client's project.
It seems to work just fine. Tape swaps are sometimes a little slow if you're sitting waiting on them...watched pot and all...
I used the unit with Dantz Retrospect on a Win 2k3 Server machine to back up and/or archive from a 1.5+ TB RAID5 array.
I managed to get it hopelessly confused once and had to pull the drive out of the unit to eject the tape, but that was probably my fault...I was doing a lot of moving tapes and rebooting machines at the same time...it's likely I either rebooted the host or (and?) pulled power from the tape library while it was in the middle of doing something important.
Otherwise, no complaints (and actually, even pulling the drive and ejecting the tape wasn't that bad...)
Todd