i will try to explain to you what 'user experience' means in practise.

when i tap on my iponhe 3g emial- i tap on it instantly it brings up my mails, and i can instantly view them..when i do this on a 3gs same thing happens

when i open up my ipod/phone/browser/simple or medium drain app etc samething happens.

on the other hand when i open my gps - the iphone 3gs has a sensor that tells me which way i am going, when i open a draining game the 3gs plays it better, when i open the camera the 3gs has focus.

these are user experiences- based on practise..

not that it has a different cpu archeticture..