The combination of direct-access buttons and big virtual buttons, so that you can use each when appropriate, makes Panasonic's touch-screen interface one of my favorites. It works most seamlessly if you use two hands, though (operating the buttons with your right thumb and navigating the screens with your left thumb, almost as if you're texting). You can also program the Q.Menu/Fn button to go directly to any other specific setting that's in the Q.Menu (top).
That said, my main frustration with the interface remains that you can't lock the AF area to prevent it from moving when you accidentally touch the center of the screen. I had to readjust it back to center between almost every shot because of this--an immensely frustrating exercise. (The second screen from the top shows the dynamic-tracking autofocus area, which doesn't have this problem.)