I think what you're referring to is the RIHD feature on the onkyo, which allows the onkyo to control other devices with HDMI. I confirmed that I'd indeed turned it off and my problem still exists. I guess I can't use my onkyo as a hdmi switcher for the 103 without using the dual-display mode and sacrificing audio quality.
I seem to have missed the audio quality issue with dual display. Please elaborate. I just connected both HDMI 1&2 to my Radiance (see above) and activated dual display to try to correct a green screen issue when switching between the two. The S&M Montage played DTS MA 48K according to the Oppo for both inputs. Regarding my comment above as to "dull" color. The highest resolution vertical pattern on the Chroma Burst pattern is definitely LOWER in color saturation if HDMI 2 is the input. Color space for both is set to 422 36 bit. Radiance settings are identical for both inputs. TV is an Elite 70X5.