Well, I too started with iOS and liked iOS for a long while. But as they phones came and went, the quality went with it. It seemed like the extra money that you spent didn't go towards developing a stronger glass, or better camera, but to line the pockets of Apple.
That being said, quality is top over Android and iOS phones in my opinion. I've found that the Nokia 1020 (big ass camera version) is as solid as the Nokia I had in the late 90's, early 00's. You drop a iPhone or Android phone, you are likely to crack the screen. You drop a Nokia, you are likely to crack the floor! So if you tend to have butter fingers, Nokia is awesome for you in that alone. Plus my 1020 came with a wrist strap (similar to a point and shoot camera) and that's handy as heck. Makes fishing it out of a pocket easy, and provides secure feeling when it's around your wrist.
Reason 2: Privacy. Windows phones don't automatically launch apps by result of opening a different app. Thus for there are no "app killers" in the market unlike Android in which is flooded with them. Android is by far the biggest culprit to data mining, and as a consumer, I don't like my data is being used by an app I am not launching. Not only can it mine your data, but it does put a drag on your phones resources, but doesn't help battery life at all either.
So reason 3, goes starts where reason 2 left off. Battery life. It's freaking sweet. Wicked Awesome. AND Totally bodacious as well. To put into perspective, I recently returned from a trip from Central KY to Gatlinburn TN. It's about a 3-4 hour drive pending traffic. The entire time driving down, I used Pandora streaming over Bluetooth in my car. Following the constant drive, came a few conversations with friends over the phone to find out where they were, as well as taking pictures while we were out and about. The battery started at 100% after about 13 hours of constant use from streaming music, making calls, taking photos, and surfing the internet, I was down to about 25% life. Right before battery saver (a default application) kicked in at 20%. According to Battery Saver app, I still had 3 hours of life left in the phone. So power user friendly that's for sure.
Reason 4: OS never lags. Well OK, once in a great while, it'll do something stupid and need a hard reset. But nowhere nearly as much as iOS or Android platforms. At work it seems most people use the Samsung Galaxy 5, or iPhone 5 or 5c. And at least once a week, I see them resetting their phones. In the last 60 days, I maybe reset it once, if even that. Not to mention, when I did the windows 8 to 8.1 update I didn't feel the need to blast Windows for taking up all of my storage or anything like that.
One Drive to rule them all! One Drive as awesome. I use it mostly for photo storage, or transfer, but if you have a good service provider (for me it's AT&T and I've yet to experience bad service), you can use One Drive for so much more. Store videos, watch them over wifi/4g, document transfer, whatever you like to use cloud storage systems for.
I am not a fan of voice command assistance, so I don't use Cortana. But I hear she's way better than Siri.
Other worth while mentions are the home screen with Live Tiles. It's nice not having to launch an app, to check if you have something there that needs attention. And the adjustable tile size, is pretty cool too. There are some really creative people out there that know how to set up sweet backgrounds using the transparent tiles. App market is good despite the bad press it gets. Although there are some apps missing that I wish would make it to Windows (like a NHL app) but I can make do. Camera's are awesome. Even the lower end phones seem to get a worth while camera, and if you go for a higher end model you'll get a really good camera that not only looks good on your phone, but pretty darn good on a computer screen as well. iPhone and Android do take good pictures ON THE PHONE. But look at them off of their fancy screens and introduce them into a traditional screen, and blah. High noise, and crap color.
Down sides: Internet Explore kinda sucks. But good news is, they are working on a replacement for it. I'm normally not the type of person that goes out looking for 3rd party explores, so I've just been making due with it. When clicking on a notification from the top bar (notification center) and launching it from there, some apps don't actually update the tile as being updated, and still show you have notifications. It's petty, but can be annoying as crap some times.
The best part will be watching your friends struggle with os problems, while you continue to use the Windows OS with out problem. Sometimes to be a dick, when I hear the die hard android users at my work complain about their phone issues I look at mine and go, "Yeap!, still running strong!"
Windows is similar to iOS as far as home screen goes, but I think you'll enjoy it better. You can personalize the home screen just how you like it, and then slide over to a full list of all apps similar to android.