It's been a week, since I upgraded. It was great at day 1; everything is faster, all apps work great. I noticed a copule of things, though, after a week. Never been rooted.
1. battery seems running out quicker. Typical (heavy) usage pattern would last 8 hours before low battery warning. Now, maybe shortened by an hour or so. My wife also feels that she's experiencing the similar shortened battery life, given that we're not doing anything different than before the upgrade.
2. My Note lost 5GHz wifi connectivity. I used to connect just fine before the upgrade. Now, I can see all the 5GHz wifi signals, but the phone just will not even attempt to connect. Just says "saved, secured with xxx". No activity such as "connecting..." or anything. My wife's Note is working fine connecting to 5GHz. I upgraded both phones at the same time.
3. I feel that I've experienced more crashes. Maybe 4~5 random crashes over the week period. Even the phone app crashed once. Power cycle fixes things.
Any suggestion from the experts? Would I be able to re-apply the same update with Kies tool?
Edit: I ended up getting a replacement phone due to the 5GHz wifi issue. New phone works ok with 5GHz wifi.