Outlaw uses Cirrus Surround to get 6.1 distinct channels but DPL IIx gets 7.1 distinct channels. With Cirrus the 2 rears are in mono. With DPL IIx they are in stereo. Also as I understand it, Cirrus doesn't adjust the side surrounds when the rear surround is on. However in DPL IIx, the side surrounds are adjusted to compensate for what is sent out on the rear surrounds.
Here's a thread with more information on
PLIIx .
Will