Usability, iOS 5 and Siri. Beyond the identical exterior lies the hard work that Apple put forth on the inside. An upgraded processor, an improved antenna and camera. The other big story
Apple iPhone 5 Written Review by Taylor
iOS - Wikipedia
Nearly two years after launch, Siri seems to exit 'beta' with iOS 7 - 9to5Mac
Apple iPhone 4S review: Fast 4ward: Siri, iCloud, iCloud apps, iCloud sync, iCloud Mail, iTunes Match
iPhone 4S Review
Review: Apple iPhone 4S for AT&T: Menus : Menus (Phone Scoop)
iPhone 4S Review
In depth review: Apple's iPhone 4S running iOS 5
Siri - Apple iPhone 4S: Thoroughly Reviewed