Finished reading many of the posts here and got a little amused. I didn't root my phone, thought GB was not so bad, but I see most here had to root their phone to get ICS before the official upgrade. They have problems with the unofficial ICS and now they want to go back to GB.
I just waited it out, woke up on Monday morning, ICS update had been downloaded and I hit Update. It took about 10 minutes for the entire process, then another 10+ minutes to update all the apps that needed ICS update. The only thing I lost was my Playlists on the Player app.
My battery life seems to be a little better, the phone seems a little zippier, I like the face recognition (really quick) unless the lights are all off
. I am having to get used to not having the contact list in the phone app, but no biggie. I do like all the UI updates and I am a happy camper.
I am posting this just to have some balance here, when someone else waits for the update and is affraid to update based on this thread. If you haven't rooted and tried to update your phone with a pre update ICS, then it appears you got trouble ahead. If you just wait, from what I see it pretty clear sailing. Not that I have ICS I am not sure I need to go out and get the SIII, just sit and wait for JB.
Wolfie