Well I was jailbroken on 2.1, but I only had a few apps I was going to lose, so I did the upgrade. The first thing I noticed is that the upgrade was FAST and EASY. It did not erase music / apps when it updated... the whole process took about 15 minutes. There's no way it re-synced 10 gigs of music and 50 apps in 15 minutes. This is a MAJOR improvement as far as I'm concerned... as it makes the upgrade painless. Overall 2.2 seems to be much more responsive. Menus definitely load faster, and overall the phone is much more responsive. Safari has a new look and seems to load pages faster. The look of the iPod has changed slightly... cover flow MUCH more responsive and smooth. Photos scroll faster and smoother. Camera app opens probably twice as fast (at least for me). Contacts load / scroll faster. Overall I like it very much!
One interesting thing I noticed... I had changed my carrier name with Erica Sudans "Make it mine" app (or whatever it's called...) the update did not change this back. Weird...
There are other things I notice as well... but I have to start doing work before my boss shows up
