First impression: wow!
I received my 804 a few days ago, but have waited until I had time to dedicate to setting it up.
I used the auto audio configuration twice, but I still need to tweak it.
I, also, had bought an Oppo DV-970HD and had about an hour of trouble getting my SACD's and a few DVD-As to work properly with the 804 and my Samsung HL-S6188W. After reading the support documentation at Oppo's website, I found that I had to switch the DV-970HD's HDMI interface from the default 480i to output 1080i.
"According to the HDMI specification, the bandwidth available for digital audio is proportional to the total bandwidth used by digital video."
Strange, but had to be done in order for those high resolution formats to be played. One of my Porcupine Tree DVD-As was playing very loud in the Front Right and Right Surround channels and it was distored; sounded aweful. All of my SACDs would not play at all. The 804 would briefly flash "PCM" and "Stereo" every 5-8 seconds. After I changed the Oppo's HDMI output, everything has been playing beautifully!
So, thanks, Onkyo! Another wonderful product.
Now, I'm still waiting on my Klipsch speakers to arrive.