Not trying to start a flame war. I am finally switching away from my trusty Nokia Lumia 920 because the browser wouldn't load m.uber.com and WhatsApp says app will be gone at the end of the year. I like the snappiness of Windows Phone and iPhone UI. Haven't checked Android phones recently but years ago the UI was laggy and no one except I seem to notice.
Also know that sideloading apps, blocking ads in apps etc. is much easier on Android so I am hard pressed to decide between the two.