Definitely a good point on the II. Also, besides testing them, it is a good idea, if you are doing a specific backup (say when you are upgrading and you need to restore), it is a good idea to make several backups. Check the size of each to insure they are all the same size. One could be corrupted while the others are not.
If you really want to be anal about it, install the new version on a sandbox, and restore to there first.
