in my experience, Matrix Stereo has the same signal going to all channels, so i use it sometimes when i listen to electronic music; then, the sound is spread all around the room, including overhead. i could call it 6 channel stereo sound.
my memory does not last long enough for me to remember differences in sound after i switch from PLIIx Music to Neo:6 Music; it seems to sound quite the same, but i can't be sure.
one advantage of PL is that it can give more than 6 distinct channels compared to a max of 6 channel with Neo.
as a side note, when i play a movie in Dolby Digital 5.1,
i also use PLIIx Movie to decode the 2 back channels for a total of 7+1 channels. Using 5.1, there seems to be a wall 1 foot behind my head and no realistic sound comes from further back. PLIIX Movie solves that to my satisfaction, in effect increasing the depth of the sound stage behind me.
the difference is very easily heard if you play Super 8 (the scene when the train comes from the back of the listener) in 5.1 or 7.1; a world of difference and a much better rendition.
others with more experience than me might tell a different story.
Edited by J. B. (03/17/12 06:24 PM)