We received the KitKat 4.4.2 update last week and there in my opinion no difference between it and the 4.4 update. Other than stability for some features and security improvement there is only one difference. That is the transparent status bar and on screen buttons only for the lock screen. We saw no reason for the update on Nexus 7, 10, and 4. New improvements have been made for the Nexus 5 that are noticeable specifically for the camera.