iPhone OS Update and Clean Restore
I am currently running OS 4.1 and I am looking to update to 4.2.1.
In the past I have always backed up using iTunes, created a custom IPSW using PwnageTool, updated, and then restored from my backup.
However, I was recently poking around in my iTunes backup files using iPhone Backup Extractor, and I noticed that there are all kinds of old preference files from Cydia packages I have uninstalled a long time ago (I actually upgraded from an iPhone 3G to an iPhone 4) as well as tables in my SMS database from iRealSMS (which I only had installed for a little while).
So what I would like to do is update to 4.2.1 completely fresh without using a backup. But, I'd like to keep my purchased apps and my saved data from my games. I'm thinking I should just back up my jailbreak preference files from the var/mobile/Preferences folder and selectively restore those I want after the restore, but this won't give me my AppStore application preferences back. Does anyone know where those are saved or have you done anything similar to this?