Yeah Mark, I think the main difference between the default "Audyssey" and "Flat" setting is the gradual rolloff in the highest frequencies. I'll have to give "flat" a try. For me, I see a great improvement during movies and music. The type of results you get can vary depending on how well you followed the initial setup from various locations. I've probably run through the setup of 8 locations 5-6 times, and have it down to a science now.
chirp chirp chirp
ps: I will say that I agree with Alan on the auto setup of my old 2805, it did make things sound worse, not the case with Audyssey, and I can speak from actual using the product. DV I only use late at night when the family is trying to sleep. DE is always on.
