This question is perhaps a followup to a cryptic remark made by Meanie on another thread. You can flash a new ROM or you can restore a NAND backup made by someone else and you can also (in some ROMs) use the Qtopia backup/restore utility to restore a backup made by someone else. What gets changed in your Zaurus with each of the three possibilities? I can make some guesses but I wonder if someone knows for sure.

A related question: how does one inspect the contents of one of these backups? Can they be mounted as loopback devices?