OK all.. it took about 5 hours for the index to complete (just over 50,000 files)... I'm listening to the same track from two different sources: from the SB/DAC and from the Oppo.
The SB/DAC is feeding my Anthem D2 via Audioquest King Cobra RCA's into the "CD" inputs.
The Oppo is feeding the D2 via HDMI cable.
D2 has all room correction turned off and subwoofer settings are the same for each component setup within the D2.
The differences are very subtle between the two, but I'd say I'm giving the edge to the Oppo. It sounds a little more lush and full than the SB/DAC.
The Oppo has balanced stereo outs for 2 channel, but I don't have any extra XLR's laying around (just ordered a pair) so I will have to wait to get them before setting that up, but I'm sure that will make the Oppo sound even better.
Navigating around with the Oppo iPhone app is VERY similar to the iPeng app for the SB, with the edge going to iPeng.