Antivirus War stories

I’m looking to switch from Command Antivirus to some other AV solution. I have Win9x, NT 4.0, NetWare 4.11, and will soon be adding Win2K Pro and Win2K server. I want real examples of why not to use Product X, or why I shoud choose Product Z. Specifically things like …
1-Ease or difficulty to set up auto updates, etc on all the aforefmentioned OSes.
2- Time spent repairing PCs corrupted by bad AV updates, etc.