[imcarthur]

I think that you are focusing in the wrong direction. 5.1 vs 7.1 vs DTS vs etc is just decoding. More channels. Before you leap up & buy more electronics to 'upgrade' an existing system - ask yourself: "How does it sound now?"

Play some music - not just film. Not so good? Too little bass? Too much bass? Vocals sound like crap? Highs sear your face? Then look to your loudspeakers first. This is typically the weakest area in most home theater systems. In the old '2-channel days', speakers used to consume 1/3 of the whole hifi budget. Now people are buying 5 + sub or 6 + or 7 + speakers rather than only 2 - but they haven't increased their budget allocation. So the quality of the whole system suffers.

Listen to a bunch of them. They should match tonally - all the way around although the left/center/right are the most critical for film. But they must sound good or any money you spend on electronics is a waste.

Disclaimer: I am in the industry & I do sell loudspeakers.

Ian