Well, think about what you need the processor for. The UI is fluid on the N9, Android is not the most performant operating system, so a faster CPU merely makes it adequate. Videos run just fine on the N9 as well, though perhaps you can think of some corner cases were CPU actually matters. Where CPU can still make a difference is in very demanding applications or games. This will only rarely make a difference though, because generally apps for Android are built with the lowest common denominator in mind, while all apps for the N9 can take full advantage of its capabilities if they need to, because they are obviously directly targeted towards the device.