Looks good so far. It would be handy if Google and phone manufacturers launched a what's new screen after the update that had a bit more detail than 'android upgrade, wifi improvements...'
Notification pull down is more customisable - you can choose whether to show the volume or brightness sliders.
Handy being able to have the home screen in portrait or landscape or locked in portrait.
The way that the soft keys disappear to allow full screen has been improved (now swipe up to get the soft keys where you've chosen to hide them).
You can say OK Google after you launch Google by swiping up the home key and it responds (I use a voice search icon so no great change).