I've been through all the phone OS's this year, including BB10, courtesy of free review samples (which have been returned.)
I think the quote that Windows Phone is good for people who don't need a smartphone is pretty apt; even though Android is a data-sucking mess, it gives people the apps they want.
BB10 is much more polished and will also run many Android apps from the Amazon Android App store, but the current phones have older SOC's in them, and battery life is poor. The BB Z10, essentially with Qualcomm iPhone 5 innards is particularly sweet to use. No-one trusts BlackBerry any more, and the Priv was an over-priced mistake.
Windows Phone history has for the most part been a dog's breakfast. I have a Palm Treo Pro here from 2008. It was operated by poking the tiny screen with a stick. At least we've moved away from that.
Of the current epoch; Microsoft have completely decimated consumer faith in their phone OS; Windows 10 upgrades which don't arrive, the 'app-gap' which just gets bigger by the day, and the crazy notion that if we all hang on just a little longer, things will be Better Tomorrow. The Lumias (and the Blu) phones on Windows 8 are excellent in almost every way, even the tiny Lumia 435 ( £55 from Sainsburies) is sweet and powerful. But it's not what people want.
The tail of this story is that, after a radical overhaul of what I do with with my phone; check emails, use Skype, send texts and make phone calls, Windows Phone 8 offers more stability, less background data use, and less PAYG mobile-data expense than either BB10 or Android.
So I have an excellent dual-sim £60 Blu Windows JR LTE, on WP8.2 which gives a three day battery life.
The joke that the Windows Phone is for people who don't need a smartphone is quite true. I'm a low -end user.
My friends think Windows phone is for grannies, but they're paying £300 - £400 a year for their contract smartphones.
You pays your money, you takes your choice. WP8.2 (Denim) is a pretty sweet place to be, and there's no Google data-mining. That's the real benefit.
The downside is that if you switch off social networking, and stop taking photos of yourself, your food, and your privates, nobody hangs out with you. So people buy the phones which enable that.
Windows Phone is just too 'adult.' Perfect for me.