Jellybean is going to ruin the iPhone5.
From what i've been reading, the iPhone5 has better processing speed then the s3, but the jellybean update is supposed to improve the processor speed & then it comes with GoogleNOW which is supposedly really intelligent -
"Perhaps the most tasty new feature in Jelly Bean is called Google Now -- a feature that lets Google pretend it's reading your mind by drawing on your search history and the location data created by the movements of your Android device.
The Google Now feature is activated by tapping on the search box or swiping up from the bottom of the screen. This pulls up Google Now cards that are filled with up to the minute, contextualised information. Google Now learns when you commute, for example, and tells you traffic information at those times. It also shows you the weather for your location and your work. If you're near a bus stop it can tell you when the next bus is due.
The system can also tie in with your calendar so when you have an appointment coming up it reminds you and also nudges you when you have to leave to get there in time, as if you had your very own PA. It even gives you the relevant public transport information.
Google Now can also automatically update you on the status of something like an airline flight you're getting, or your favourite football team scoring a goal. You don't even need to tell your phone which flight or team to update you on -- it works that out from your searches."