Answer to you last question i still have a MAcbook Pro and a iPad,
Battery life is superior on the GS3 though its a fact.
You cannot loath android keyboards since there is so many of so many designs. Swiftkey 3 has some serious advantages. Use an iPad keyboard for 5 minutes and you will be sick of reach the top of the screen to stop auto correcting a word you dont want it to. like it or not choice is good, you can probably find a iOS keyboard on the play store.
Just so you know.
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Dude they have unlocked Bootloaders and you can put any custom Rom on you wish. CM10 rocks! you can even load on vanilla android.
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i think half the problem is that there is a lot of preconceived ideas about android which get propagated around forums and the press.
i know i was certainly a non believer until i jumped ship. the reason i jumped was 400 GBP in my bank to move. i moved for the money mostly on a deal i was offered and trade in on my old phone and a brand new S3 for free.
What i found was surprising and nothing like i had been led to believe.
i encourage people to give it a go. i loved my iphones but i cant live with Apples slow pace of change. it just doesnt suit me.
As for battery, we will see which is the winner as the GS3 is much newer so maybe the iPhone5 will also improve on this. But I admit that the battery is bad on the iPhone. Never worked with an Android that improved on it but havent used the GS3 extensively either.
Basically it boils down to that Samsung makes decent stuff (the iPhone is after all basically a Samsung product) but Googles software is crap