Now as far as the original poster concern over factory reset after installing and major upgrade, it's a matter of choice. I have worked on enough Android phones over memory full issues to know that the o/s does not release some memory space due to whatever reason, that can only get reset by performing the factory reset. So my thoughts on the subject is junk get left around, and I like to think I am cleaning it up. I always think of Windows Registry and all the crap left behind! And as far as redownloading all the Apps, when Playstore updates, select Menu, My Apps and you can slide between INSTALLED panel to the next panel that says ALL, which lists every app you have installed (it doesn't forget, unless you a different Gmail). Simply install from the list. Or go to market.Android.com and log on with your Gmail to view the same list (and it even has all your other devices listed too). Loving ICS on my Nexus.