I was having some issues with my Rez before the update. The last thing I wanted to do was a factory reset. So, I backed up what I wanted, like my text messages, for one and pulled the trigger. Then I got ICS and a few mentioned problems, especially the rapid battery drain and heat. Had that with one of my 3 Tbolts and it sucks. After reading up on here, I again did the reset and now things are AWESOME!
So honestly, I believe that anyone who has ICS should reset!

I want to thank everyone on this forum for all of the great info y'all provide. I don't think there's a button to push to thank everyone, lol.
I've learned so much and am very grateful!
Peace and chicken grease!!!