iOS: Advantage of fresh install over backup restore?
This is Alex from Reincubate, I work on the iPhone Backup Extractor.

Setting up your iPhone from scratch will mean that you lose your personalized settings, while restoring from previous backup will revert the settings to the moment of the backup. If you have nothing against taking it all over again with your iPhone you should set as new, but if you are in a hurry and want to speed the process up restore from backup.

Hope it helps.