Some of the observations after one day of usage : (and I hope it will answer your queries as well)
Xbox Music Performance = Still Slow like before
Nokia Music Performance = same as before
Colour Profile = We can change saturation levels and this made red/cobalt accent less hurting to eyes during night time.
Glance Clock didn't effect much on my battery but unlocking process is bit long because first we must double tap and then slide to unlock.We can turn off glance clock if we want or used "timed" mode.
Some of the animation screen times have reduced maybe by 0.2-0.5 seconds.
Radio works well.
However I saw some slight frame drops (very very minute) in settings app which you won't even notice until someone points out.However in remaining places , everything works almost same as before.
IE has always been a smooth experience , So I didn't find any change in it .Its very good performer.