Neo6 utilizes multi-channel just like PLIIx but, like Eric says, it has a more central, more "up-front" rather than surround presentation. I don't like it either and now I exclusively use PLIIx. When you use PLII, make sure you disable the wrap-around effect so that you hear ambience rather than the band wrapped around you.

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated