Basicly the only time I use it, is for Satelite when the material is not PL based, and SPM's are not having any effect on the soundtrack for an action adventure type flim.

DPLII does not have anything to work with, and basicly your hearing the flim poorly distributed just in your fronts. Then I'll throw it into 6 stereo mode to 'fake me out' that its a surround experince.
I do occasionaly use Dobemans method, for CD's, to better listen when I'm moving around the house but this can depend on the CD. Many still sound better even listening off, - around the house, on 2-channel.