I didn't switch, per se... I actually went through a long and involved trial and error process to find the devices that work for me. I've had eMacs, iMacs, and Mac Minis, Linux boxes, and Windows boxes, and I've found that Windows 8 works best for me (for what it's worth, prior to Windows 8, OS X worked best for me). I've had an iPad Mini, a Nexus 7, and a Surface RT and found that the Surface RT works best for me (I don't think that iOS scales up to the tablet very well and I just don't like Android very much). I've had Windows Mobile, PalmOS, Android, Windows Phones, and iPhones and I've found that the iPhone just works best for me.
I can tell you some of the reasons that the iPhone works best for me: one, it just works. I've had hardware and software problems with every other phone platform I've tried, but I've never had a software issue with iOS, and the one or two hardware issues I've had have been rectified quickly at the Apple store. Two, it integrates with every service I use seamlessly: Office, Exchange, PhoneFactor (now Microsoft Azure Multi-Factor Authentication), Reddit, Feedly, Flickr, Lync, Skype, Cisco VPN, all the social networks, you name it. Three: OS updates. I cannot tell you how agonizing it is waiting for OS updates for Windows Phones and, even, the few Android devices I've had.
So yeah. There's that.