Dean, just to make sure that we're talking about the same thing, the various ambience extraction modes(DPLII, Neo:6, Neural Surround, Logic 7, etc.)aren't really "DSP" modes(maybe you just used the term in a very broad sense). The difference is that the extraction processing takes out natural ambience which is present to varying degrees in all 2-channel material and then redirects it to the surrounds. The various DSP modes(Jazz Club, Stadium, Beer Garden, Sportin' House, etc.)add an arbitrary amount of artificial reverberation and other processing.
I certainly wouldn't characterize it as "one size fits all", but I've never come across a 2-channel source that wasn't improved at least to a small degree. The amount of ambience mixed in varies and to a limited extent the Dimension setting in DPLII can be used to send more or less of it to the surrounds. Suddenly switching from surround to straight stereo demonstrates how the sound field suddenly collapses toward the front.
