I will be getting a commercial plasma TV that doesn't have an internal HDTV tuner. I save money and the picture quality is better than the consumer sets. I know that I can't get local HD OTA with the TV alone. Is the quality of OTA using a built-in HDTV tuner better than hooking up the antenna to the TV ANTENNA/ CABLE IN input on the 622? Other than the price of the antenna, do I have to pay for OTA through the 622? Or do I only pay for the local channels add on, which provides locals via satellite? Finally, does the locals add on include HD locals? Thanks.