I was told by Symantec tech support that you can only restore individual email messages/folders from a full Information Store backup. If you try to restore an incremental or differential then you will restore all backed up data, and probably have a lot of upset users!
Now I only run full backups twice a week and rely on the "Restore Deleted Items" feature in Outlook.
Thumbs down to Symantec on this one.
Jerry, I suggest you look into the "Continuous Protection for Exchange". It sounds sweet but I was also told by a rep at a seminar in San Francisco that I could not use it because I am on a cluster.