50phd8uk blades

I know the newer hdmi blades show full 1080i resolution for the 50phk8uk, how about the dvi blade? When using my directv hd tivo ,I output sound to receiver optical in. and use component for video. I'm afraid I might lose the optical sound ouput from tivo if I use the hdmi. Will there really be a picture quality difference between dvi, hdmi or component with this set up? keep it as is? Any help is appreciated.