1. A useful device. - I am getting tired of seeing Android devices with low memory warnings. Be it an HTC Desire or Samsung Galaxy Ace, you get the triple: Viber, Whatsapp and Low Memory Warning. Android may be okay on the latest hardware, but the VAST majority of Android devices are low-end and so close to useless, you have to be a pedant to draw the distinction. By contrast, my Lumia 620 has 26 apps/games and still shows 3.5Gb free.
2. Security - Android does the triple whammy of having several security breaches, not being a walled garden and not allowing security software special privileges, so any step you take to improve your situation is a waste of time. The latest is a flaw in the Java random number generator which means app encryption is not safe. Don't forget personal information is kept on these devices. Google's attitude here is shockingly irresponsible.
3. App Availability - Yes, the Windows Phone Store has a third of the apps available in theory, but how many times have low-end Android users selected an app only to find it won't run on their Galaxy Ace? 99% of Windows Phone apps will run on low-end hardware like the Lumia 520 or HTC 8S.
4. Support - Given that most new Windows Phones will be Nokias, how many low-end Android devices come with free turn-by-turn navigation?
5. Updates - Those of us who bought early are in the process of receiving their second OS update on their devices with two more due by the middle of next year. Android devices are updated may be once in their lifetime.
6. Consistency - Buy a Nokia, Samsung or HTC Windows Phone and you will get a very similar experience, meaning that if you swap from Samsung to Nokia, you won't have to learn a different way of doing things the way you would jumping from an S4 to an HTC One.
7. Freedom from Bloatware - Good old Samsung junk half the memory of the GS4, filling it with stuff users never asked for and when they complain, Sammy says: 'buy an SD card.'. My, aren't we lucky?
8. Integration - Windows Phone is an important part of their 'three screens' strategy for the future of computing. Contacts, calenders and even xbox on the phone are tied to the Microsoft account, meaning they are synchronised and available either through outlook.com or the apps on the desktop of Windows 8. This means that if you are arranging a date on the phone, you can use your PC to check if the 24th is free without having to interrupt the call. Any changes on the PC will be synced to the phone and visa-versa without any user having to remember to do it.
9. Privacy - Microsoft don't track the position of your handset or trawl through your private email looking for keywords. Google do so they can target you with advertising. It seems that when you put your (& your family's) personal information on your device, it no longer belongs to you, but to a multi-billion dollar company who have published people's private private information on line - ie: the logins of private unsecured wi-fi networks.
10. Reliability - Windows Phones are extremely reliable. No having to hook out the battery or periodically reset the device, no having to continually manage what apps are using up resources despite not doing anything except waiting for a response from you. Windows Phones just keep going, doing what they're supposed to.
I have now been using Windows Phones for over two years, on four devices and I have never been less than happy with the experience. I see no alternative for a smooth, integrated experience which doesn't invade and commodify my personal privacy.