cd:
2 channels 16 bit 44.1khz
dynamic range (headroom) 96db

dvd-audio:
6 channels (5.1) 24 bit 96khz
dynamic range 144db

dvd sampling rate = 4.3 times higher than cd
dvd quantization resolution = 256 times finer
than cd

sorry, i used the term "saturation" loosely, from my experience as a session bassist.
32 tracks (2" analog tape) has to be mixed down to 2 channels for stereo, then converted to digital at the above rates for the cd format.
saturation occurs when the available headroom is exceeded. with analog tape there is some forgiveness in the sound if you reach saturation for short bursts. in the digital domain there is no such forgiveness. exceeding headroom limits is a no-no.

all i am saying is, having 5 discrete channels (instead of 2) with 144db of headroom PLUS a discrete .1 channel for lfe changes everything....artificial or not.

most current dvd-a/sacd software is re-mixed from analog masters and live recordings of symphonies, etc., but that will change soon.

i'm looking forward to being able to play back 5.1 recordings done completely in the digital domain that take advantage of the endless possibilities that stereo does not offer.