I've been using WP since Lumia 800 was released, I basically got into WP because of Nokia .. Lumia 800 and N9 were the most beautiful things back then. Since WP8 came out, I found all the apps I need, although I agree we need more.
Also WIndows Phone was beautiful, smooth , lag free , elegant, simple (WP7.5) , stable and you could customize it to an extent. You were getting all this out of the box.
WIth Android my problem is you have to work on the OS, it is still not lag free, stable, elgant and smooth like WP is.
When ICS was around I was so angry at Google & HTC because none of the devices were getting proper updates, devices were getting updated and discarded. The apps were and still donot have a common set of guidelines (HOLO UI is changing it slightly). I mean one app had a back button on the top another had a back at the bottom, some apps used the physical button. Oh my God what a complete mess.
I had to root my desire and flash thrice since HTC wouldn't release updates. CM team is the saving grace of Android
That said, I used the LG Nexus 4 for a few days and I cannot tell you how happy I was to see Android running so smooth and lag free. I don't know what they did there but if that is the way all Nexus in the future are I might get one as a secondary device.(**** camera though)
I couldn't live with iOS because the devices were too costly in India, iOS cannot be made personal and all cool features I wanted meant the device had to be jailbroken.