Hi,
I use a Windows Phone device as primary device.
Firstly I had a Lumia 710, but now I have a Lumia 520, in order to upgrade to WP8.
In fact, I like Windows Phone because of its user interface and because the apps are API-restricted avoiding malware and ensuring good performance.
Obviously, the main problem is the lack of apps. Now, I am using also Android as secondary device, because I have been porting my app (Comic Time) to Android.
I also like Android, but I miss some awesome apps from Nokia and Microsoft like offline maps and offline music service.