Here is a video of Nokia N9 running latest software update PR1.3. UI is  smoother than ever and touch response is almost instantaneous. Even multitasking is very smooth and responsive. Seems that most of the 1000 changes which has come with PR1.3 were related to small bug fixes and went into enhancing smoothness and performance of N9.

Check the video below.

[youtube=http://www.youtube.com/watch?feature=player_detailpage&v=Q1Hd5SHCZxs]