Yes, I have used WP7. It actually feels cluttered. And I said, when directly compared to MeeGo, it lacks simplicity. Tiles are ugly, and ruing the interface, they seem out of place. Resolution is used badly, like in the QVGA days. Third of the screen's space has been taken by PEOPLE for instance. I know what the hell it is, I tapped on it. This is the reason why WP7 is fast. However, you can really notice its flaws when compared to MeeGo, even Maemo 5.