My understanding is that the Oppo uses both the 5.1 left/right outputs as well as the XLR left/right outputs for generating sound from both multi-channel movie source and stereo music sources, so he should be just fine.
The Oppo XLR outputs use a single 8-channel ESS DAC chip that stacks the internal DACs in parallel for output and also uses a much better analog output stage than the 5.1 RCA board, so audio should be better on the XLR/RCA output section anyways.
The Oppo XLR outputs use a single 8-channel ESS DAC chip that stacks the internal DACs in parallel for output and also uses a much better analog output stage than the 5.1 RCA board, so audio should be better on the XLR/RCA output section anyways.