I just bought the MX800. All I can say is me and my whole family prefers the MX500. I don't know what they were thinking. The button to turn on the backlight is significantly harder to press, requiring a different hand hold to apply enough pressure. The transport buttons that are used frequently for skipping through DVD chapters and PDR content are missing and replace with something that could easily go into the LCD screen. The play button is moved from over the thumb pad to under where it's harder to reach. In my opinion the MX500 is a much better feeling remote in many ways. On the other hand they did improve the thumb pad operation, they improved the way it handles toggle bits and you can connect it directly to your computer to configure the remote. Some of the reasons that I haven't sent it back.