Fixed for me in PR1.3 is a annoying problem I had with my caller ID.
Previously when on a call and a 3rd party would ring me, the phone would beep to alert me to the awaiting call but the screen would only display 'incoming call...' no name even if the person was in my contacts or a number if they were not. When i'm on a call now and a 3rd party rings me the caller id works correctly, it beeps and I get displayed on screen either a name if the caller is in my contacts or a number if they are not.
Okay, so it seems that the scrolling in general has been changed a little - there seems to be more resistance (which i like)
Messaging app seems to be less laggy
Music player less laggy
Everything in general seems to be a lot more polished
Lumiaman, perhaps you should do a clean flash of PR1.3 on your phone? I am experiencing next to no lag now. You have to understand that even dual/quad core android phones lag, so I think you're being a little too critical of the N9