I have to disagree - I love Windows Phone Mango 7.5 - It's SUPER fast - Simple and works like a charm.
Android in my oppinion lags, is slow and looks so unfinished. And yes I know you can change themes and so, but that just makes Android slower and slower.... So Im happy Nokia choosed Windows Phone over Android.
But the best is stil iPhone with iOs. Everything works, looks good, and the apps are so much better than on Android.
And yes ... I have an iPhone 4S, a Nokia 800 and a Samsung Galaxy II, iPad 1 and a Samsung Galaxy Tab 10" - So I can compare.
And for all those - "Oh Android is open source and free for everyone. They don't stalk you like Apple and MS" - Those who say that, havent read the Google License. It's so much worse :-O