Vinny, I'm not sure why we experienced a difference in sound. I have mine set up for surround sound but having watched this movie a number of times on DVD, the surround effects were just not as good on my system through the OTA broadcast. For example, there is a scene early in the movie involving fireworks at the party of Hobbits before the birthday party. While my back speakers were certainly active, the surround effects weren't nearly as strong. I should add that I generally experience this with most OTA HD broadcasts. I'm told it is because the broadcasters limit the bit rate for the HD sound part of their broadcasts.
Dave, I shall also be buying the extended version of the final movie ASAP. I can't imagine it though since the original movie is already 3 1/2 hours!