Hey all. I'm very suspect of the different sound modes on my Yamaha RX-V 650 such as the rock concert, jazz, music video, disco, etc settings. I believe, when listening to music, it is better to listen to it without any additional "enhancements". If the producers and engineers of the source material intended for the music to sound like it was coming from a "jazz club" of "rock concert" they would have done so. The neo6 for music sounds horrible, very muddy. It seems to me as though these accomniments take away from the purity of the source recording. I'm not sure however on the difference between the 2channel and 7 channel stero modes as far as if the 7 channel takes away somehow from the original intended sound of the music. For movies, I love the DTS coding automatic options.
I have a Yamaha receiver, forgot the model, but very possibly identical to the one you own. Anyhow, all Yamaha models allows you to configure any of these mode. When I did that, I found the four DTS modes (Adventure, Spectacle, Sci-Fi, General) were preset to fairly similar parameters, so I changed it to my liking. Other music modes (Hall, Jazz, Rock, Disco, etc) can also be twigged. They sound great. I think of this as a good feature. Think about it, there's no standard sound that a Rock band is supposed to be recorded to. If you listen to a live band playing in a hall, a bar, or in open space, they'd be all different, so there's nothing wrong with these configurable modes. Perhaps most CDs are recorded in controlled rooms, but that's probably not the best place we listen to them, right? So for DTS, I made them sound like what the label (Spectacle, Sci-Fi, etc) suggest, spectacle should be "big", Adventure should have stronger low frequency subwoofer output, and so on.
I think the point that the Kid-A was missing is that there are numerous ways to tweak your receivers output to your personal liking. No setting is 'universally' best, but it's a huge benefit to have many options available at your disposal to create the best sound possible for each individual taste.