* Contacts lag is pretty much gone. This was very annoying. I have opened up apps, closed them, and then gone back into Contacts, and it still opens much quicker than it previously did.
* Haven't noticed the very annoying SMS typing lag yet. Hopefully it stays away for good!
* Safari opens faster and responds more quickly.
* Better reception?? My iPhone sits in its dock in the exact same place every day/night. After the update, I got 3G reception for the FIRST TIME while in the dock (I am in my rec room in the basement where cell reception is terrible). I loaded Google Reader and it responded very quickly. This could just be coincidence, but it's still interesting.
* Haven't checked on the "backing up." I will install a few apps tomorrow and then do a sync and see if it's improved.