A:
HDMI does transmit both hi-def video as well as sound, which means you will get the most out of your sound setup, including Dolby 5.1 or even 7.1. An optical cable would come into play if you have a receiver and speaker setup which you are NOT using to route all your media devices. The optical would output any sound from your TC to your surround sound setup. For example, you have a BLU-Ray player connected directly to your TV, not the receiver. However, it is much easier just to connect all your devices through your receiver and then just use one input on your TV from your receiver. Hope this answered your question!