Windows Phones, in their many incarnations, is not tweaked by manufacturers the way Android is, so developing for it's platform is not really that painful. iOS dominates the market, that's why you...
My Nokia 810 have a great camera, but the Apps you can get on iOS are more sophisticated. EyeEm for WP8 sucks (they are a small team, they will improve it in time) Fantasia Pinter and Fhotoroom are...
I have the Lumia 810 (T-Mobile) and I'm quite happy with it. The difference is that the 920 have image stabilization and probably a powerful software.Ah! and other than the Camera, the Nokia Maps...