Windows Phone 8 is a marked improvement over Microsoft's previous iteration. Its ability to provide "at a glance" information is unmatched. It's quick too, and it's arguably the most attractive of the popular mobile operating systems. Problems lurk though. There is no dedicated notification center, so particular notifications may slide away unnoticed after a moment if the user doesn't keep a tile for the app on the home screen. The ecosystem on Windows Phone has surpassed 100,000 apps, but it is still lacking compared with Android and especially iOS. On the plus side, every Windows Phone ships with Microsoft Office Mobile for free.
The iPhone 5 comes with the latest and greatest iteration of iOS 6. The Cupertino-built iOS is the most reliable, familiar and easy-to-learn of all its competitors. The app ecosystem is unmatched. New app developers innovate on a weekly basis, and all of your favorite internet services are likely to be represented in the App Store.