I have the Oppo 970 as well. I only use it with 2 channel, so I haven't tested multichannel with it. For CD or DVD audio I go digital from the Oppo -> Musical Fidelity X-DACv8->Musical Fidelity A5 integrated. For SACD I have to use the Oppo DACs and go Oppo->Musical Fidelity A5 int. Now the Oppo analog outputs don't compare to a DAC costing 10x as much as the Oppo player, but they aren't horrible either. For a $150 player they are pretty good, and better than most mid-fi receiver DACs I have heard. Of course there is the whole analog path in the receiver to contend with, in my case I am using the same analog paths through the Integrated regardless of which DAC I am using.
Mastering and 2 Channel: Wavelab 9/Bluesound Node/Pro-ject RPM 5.1 SE -> McIntosh C47 -> McIntosh MC452 -> Focal Sopra No 2 and REL S5/SHO (switchable)
Mixing and desktop: Cubase/Squeezebox -> Oppo HA-1 -> Rotel RB-1080 -> B&W N805 and REL S2
Theater: Oppo 103d -> Marantz SR7009 -> Martin Logan Motion 4/8 7.1 with REL S5/SHO
Living Room: Marantz SR5009 -> Rotel RB-993 -> B&W N804/HTM1 Rythmik F12SE