I had a N9, and I completely agree with the person above. The funniest thing is that when I got the phone and showed it to a friend who had just received the most recent Nexus at the time, the first thing he did was just scrolling, switching between apps and admiring how smooth everything was. The illusion faded quickly when you tried to open a web page with any javascript.
As far as I know, the code behind the scenes and especially the app store were a mess, but it didn't show to the user. And of course every app could access everything.